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ZALEPLON
Overview
What is ZALEPLON?
Zaleplon is a nonbenzodiazepine hypnotic from the pyrazolopyrimidine class. The chemical name of zaleplon is N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide. Its empirical formula is C HNO, and its molecular weight is 305.34. The structural formula is shown below.
Zaleplon is a white to off-white powder that is practically insoluble in water and sparingly soluble in alcohol or propylene glycol. Its partition coefficient in octanol/water is constant (log PC = 1.23) over the pH range of 1 to 7.
Zaleplon capsules contain zaleplon as the active ingredient. Inactive ingredients consist of microcrystalline cellulose, pregelatinized starch, silicon dioxide, sodium lauryl sulfate, magnesium stearate, lactose, gelatin, titanium dioxide, D&C yellow #10, FD&C blue #1, FD&C green #3, and FD&C yellow # 5.
What does ZALEPLON look like?


What are the available doses of ZALEPLON?
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What should I talk to my health care provider before I take ZALEPLON?
Sorry No records found
How should I use ZALEPLON?
Zaleplon is indicated for the short-term treatment of insomnia. Zaleplon has been shown to decrease the time to sleep onset for up to 30 days in controlled clinical studies (see under ). It has not been shown to increase total sleep time or decrease the number of awakenings.
The clinical trials performed in support of efficacy ranged from a single night to 5 weeks in duration. The final formal assessments of sleep latency were performed at the end of treatment.
The dose of zaleplon should be individualized. The recommended dose of zaleplon for most nonelderly adults is 10 mg. For certain low weight individuals, 5 mg may be a sufficient dose. Although the risk of certain adverse events associated with the use of zaleplon appears to be dose dependent, the 20 mg dose has been shown to be adequately tolerated and may be considered for the occasional patient who does not benefit from a trial of a lower dose. Doses above 20 mg have not been adequately evaluated and are not recommended.
Zaleplon should be taken immediately before bedtime or after the patient has gone to bed and has experienced difficulty falling asleep (see .). Taking zaleplon with or immediately after a heavy, high-fat meal results in slower absorption and would be expected to reduce the effect of zaleplon on sleep latency (see Pharmacokinetics under ).
Special Populations
Hepatic insufficiency: Patients with mild to moderate hepatic impairment should be treated with zaleplon 5 mg because clearance is reduced in this population. Zaleplon is not recommended for use in patients with severe hepatic impairment.
Renal insufficiency: No dose adjustment is necessary in patients with mild to moderate renal impairment. Zaleplon has not been adequately studied in patients with severe renal impairment.
An initial dose of 5 mg should be given to patients concomitantly taking cimetidine because zaleplon clearance is reduced in this population (see under ).
What interacts with ZALEPLON?
Hypersensitivity to zaleplon or any excipients in the formulation (see also ).
What are the warnings of ZALEPLON?
If CDAD is suspected or confirmed, ongoing antiobiotic use not directed against may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of , and surgical evaluation should be instituted as clinically indicated.
Because sleep disturbances may be the presenting manifestation of a physical and/or psychiatric disorder, symptomatic treatment of insomnia should be initiated only after a careful evaluation of the patient. Worsening of insomnia or the emergence of new thinking or behavior abnormalities may be the consequence of an unrecognized psychiatric or physical disorder. Such findings have emerged during the course of treatment with sedative/hypnotic drugs, including zaleplon. Because some of the important adverse effects of zaleplon appear to be dose-related, it is important to use the lowest possible effective dose, especially in the elderly (see ).
A variety of abnormal thinking and behavior changes have been reported to occur in association with the use of sedative/hypnotics. Some of these changes may be characterized by decreased inhibition (eg, aggressiveness and extroversion that seem out of character), similar to effects produced by alcohol and other CNS depressants. Other reported behavioral changes have included bizarre behavior, agitation, hallucinations, and depersonalization.
Abnormal Thinking and Behavioral Changes
It can rarely be determined with certainty whether a particular instance of the abnormal behaviors listed above is drug induced, spontaneous in origin, or a result of an underlying psychiatric or physical disorder. Nonetheless, the emergence of any new behavioral sign or symptom of concern requires careful and immediate evaluation.
Following rapid dose decrease or abrupt discontinuation of the use of sedative/hypnotics, there have been reports of signs and symptoms similar to those associated with withdrawal from other CNS-depressant drugs (see ).
Zaleplon, like other hypnotics, has CNS-depressant effects.. Patients receiving zaleplon should be cautioned against engaging in hazardous occupations requiring complete mental alertness or motor coordination (eg, operating machinery or driving a motor vehicle) after ingesting the drug, including potential impairment of the performance of such activities that may occur the day following ingestion of zaleplon. Zaleplon, as well as other hypnotics, may produce additive CNS-depressant effects when coadministered with other psychotropic medications, anticonvulsants, antihistamines, narcotic analgesics, anesthetics, ethanol, and other drugs that themselves produce CNS depression. Zaleplon should not be taken with alcohol. Dosage adjustment may be necessary when zaleplon is administered with other CNS-depressant agents because of the potentially additive effects.
Severe anaphylactic and anaphylactoid reactions
What are the precautions of ZALEPLON?
General
Timing of Drug Administration
Use in the elderly and/or debilitated patients
Use in patients with concomitant illness
The dose of zaleplon should be reduced to 5 mg in patients with mild to moderate hepatic impairment (see ). It is not recommended for use in patients with severe hepatic impairment.No dose adjustment is necessary in patients with mild to moderate renal impairment. Zaleplon has not been adequately studied in patients with severe renal impairment.
Use in patients with depression
Information for Patients
SPECIAL CONCERNS “Sleep-Driving” and other complex behaviors
There have been reports of people getting out of bed after taking a sedative hypnotic medicine and driving their cars while not fully awake, often with no memory of the event. If a patient experiences such an episode, it should be reported to his or her doctor immediately, since “sleep-driving” can be dangerous. This behavior is more likely to occur when zaleplon is taken with alcohol or other central nervous system depressants (see ). Other complex behaviors (e.g., preparing and eating food, making phone calls, or having sex) have been reported in patients who are not fully awake after taking a sleep medicine. As with sleep-driving, patients usually do not remember these events.
Laboratory Tests
Drug Interactions
CNS-Active Drugs
Imipramine: Coadministration of single doses of zaleplon 20 mg and imipramine 75 mg produced additive effects on decreased alertness and impaired psychomotor performance for 2 to 4 hours after administration. The interaction was pharmacodynamic with no alteration of the pharmacokinetics of either drug.
Paroxetine: Coadministration of a single dose of zaleplon 20 mg and paroxetine 20 mg daily for 7 days did not produce any interaction on psychomotor performance. Additionally, paroxetine did not alter the pharmacokinetics of zaleplon, reflecting the absence of a role of CYP2D6 in zaleplon's metabolism.
Thioridazine: Coadministration of single doses of zaleplon 20 mg and thioridazine 50 mg produced additive effects on decreased alertness and impaired psychomotor performance for 2 to 4 hours after administration. The interaction was pharmacodynamic with no alteration of the pharmacokinetics of either drug.
Venlafaxine: Coadministration of a single dose of zaleplon 10 mg and multiple doses of venlafaxine ER (extended release) 150 mg did not result in any significant changes in the pharmacokinetics of either zaleplon of venlafaxine. In addition, there was no pharmacodynamic interaction as a result of coadministration of zaleplon and venlafaxine ER.
Promethazine: Coadministration of a single dose of zaleplon and promethazine (10 and 25 mg, respectively) resulted in a 15% decrease in maximal plasma concentrations of zaleplon, but no change in the area under the plasma concentration-time curve. however, the pharmacodynamics of coadministration of zaleplon and promethazine have not been evaluated. Caution should be exercised when these 2 agents are coadministered.
Drugs That Induce CYP3A4Rifampin: CYP3A4 is ordinarily a minor metabolizing enzyme of zaleplon. Multiple-dose administration of the potent CYP3A4 inducer rifampin (600 mg every 24 hours, q24h, for 14 days), however, reduced zaleplon C and AUC by approximately 80%. The coadministration of a potent CYP3A4 enzyme inducer, although not posing a safety concern, thus could lead to ineffectiveness of zaleplon. An alternative non-CYP3A4 substrate hypnotic agent may be considered in patients taking CYP3A4 inducers such as rifampin, phenytoin, carbamazepine, and phenobarbital.
Drugs That Inhibit CYP3A4CYP3A4 is a minor metabolic pathway for the elimination of zaleplon because the sum of desethylzaleplon (formed via CYP3A4 in vitro) and its metabolites, 5-oxo-desethylzaleplon and 5-oxo-desethylzaleplon glucuronide, account for only 9% of the urinary recovery of a zaleplon dose. Coadministration of single, oral doses of zaleplon with erythromycin (10 mg and 800 mg respectively), a strong, selective CYP3A4 inhibitor, produced a 34% increase in zaleplon's maximal plasma concentrations and a 20% increase in the area under the plasma concentration-time curve. The magnitude of interaction with multiple doses of erythromycin is unknown. Other strong selective CYP3A4 inhibitors such as ketoconazole can also be expected to increase the exposure of zaleplon. A routine dosage adjustment of zaleplon is not considered necessary.
Drugs That Inhibit Aldehyde Oxidase
The aldehyde oxidase enzyme system is less well studied than the cytochrome P450 enzyme system. Diphenhydramine: Diphenhydramine is reported to be a weak inhibitor of aldehyde oxidase in rat liver, but its inhibitory effects in human liver are not known. There is no pharmacokinetic interaction between zaleplon and diphenhydramine following the administration of a single dose (10 mg and 50 mg, respectively) of each drug. However, because both of these compounds have CNS effects, an additive pharmacodynamic effect is possible.
Drugs That Inhibit Both Aldehyde Oxidase and CYP3A4
Cimetidine: Cimetidine inhibits both aldehyde oxidase (in vitro) and CYP3A4 (in vitro and in vivo), the primary and secondary enzymes, respectively, responsible for zaleplon metabolism. Concomitant administration of zaleplon (10 mg) and cimetidine (800 mg) produced an 85% increase in the mean Cmax and AUC of zaleplon. An initial dose of 5 mg should be given to patients who are concomitantly being treated with cimetidine (see ).
Drugs Highly Bound to Plasma Protein
Zaleplon is not highly bound to plasma proteins (fraction bound 60%±15%); therefore, the disposition of zaleplon is not expected to be sensitive to alterations in protein binding. In addition, administration of zaleplon to a patient taking another drug that is highly protein bound should not cause transient increase in free concentrations of the other drug.
Drugs with a Narrow Therapeutic Index Digoxin: zaleplon (10 mg) did not affect the pharmacokinetic or pharmacodynamic profile of digoxin (0.375 mg q24h for 8 days).Warfarin: Multiple oral doses of zaleplon (20 mg q24h for 13 days) did not affect the pharmacokinetics of warfarin (R+)- or (S-)-enantiomers or the pharmacodynamics (prothrombin time) following a single 25-mg oral dose of warfarin.
Drugs That Alter Renal ExcretionIbuprofen: Ibuprofen is known to affect renal function and, consequently, alter the renal excretion of other drugs. There was no apparent pharmacokinetic interaction between zaleplon and ibuprofen following single dose administration (10 mg and 600 mg, respectively) of each drug. This was expected because zaleplon is primarily metabolized and renal excretion of unchanged zaleplon accounts for less than 1% of the administered dose.
Carcinogenesis, Mutagenesis, and Impairment of Fertility
Carcinogenesis
Mutagenesis
Impairment of Fertility
Pregnancy: Pregnancy Category C
In a pre- and postnatal development study in rats, increased stillbirth and postnatal mortality, and decreased growth and physical development, were observed in the offspring of females treated with doses of 7 mg/kg/day or greater during the latter part of gestation and throughout lactation. There was no evidence of maternal toxicity at this dose. The no-effect dose for offspring development was 1 mg/kg/day (a dose equivalent to 0.5 times the MRHD of 20 mg on a mg/m2 basis). When the adverse effects on offspring viability and growth were examined in a cross-fostering study, they appeared to result from both in utero and lactational exposure to the drug.
There are no studies of zaleplon in pregnant women; therefore, zaleplon is not recommended for use in women during pregnancy.
Labor and Delivery
Nursing Mothers
Pediatric Use
Geriatric Use
What are the side effects of ZALEPLON?
Sorry No records found
What should I look out for while using ZALEPLON?
Hypersensitivity to zaleplon or any excipients in the formulation (see also ).
Because sleep disturbances may be the presenting manifestation of a physical and/or psychiatric disorder, symptomatic treatment of insomnia should be initiated only after a careful evaluation of the patient. Worsening of insomnia or the emergence of new thinking or behavior abnormalities may be the consequence of an unrecognized psychiatric or physical disorder. Such findings have emerged during the course of treatment with sedative/hypnotic drugs, including zaleplon. Because some of the important adverse effects of zaleplon appear to be dose-related, it is important to use the lowest possible effective dose, especially in the elderly (see ).
A variety of abnormal thinking and behavior changes have been reported to occur in association with the use of sedative/hypnotics. Some of these changes may be characterized by decreased inhibition (eg, aggressiveness and extroversion that seem out of character), similar to effects produced by alcohol and other CNS depressants. Other reported behavioral changes have included bizarre behavior, agitation, hallucinations, and depersonalization.
Abnormal Thinking and Behavioral Changes
It can rarely be determined with certainty whether a particular instance of the abnormal behaviors listed above is drug induced, spontaneous in origin, or a result of an underlying psychiatric or physical disorder. Nonetheless, the emergence of any new behavioral sign or symptom of concern requires careful and immediate evaluation.
Following rapid dose decrease or abrupt discontinuation of the use of sedative/hypnotics, there have been reports of signs and symptoms similar to those associated with withdrawal from other CNS-depressant drugs (see ).
Zaleplon, like other hypnotics, has CNS-depressant effects.. Patients receiving zaleplon should be cautioned against engaging in hazardous occupations requiring complete mental alertness or motor coordination (eg, operating machinery or driving a motor vehicle) after ingesting the drug, including potential impairment of the performance of such activities that may occur the day following ingestion of zaleplon. Zaleplon, as well as other hypnotics, may produce additive CNS-depressant effects when coadministered with other psychotropic medications, anticonvulsants, antihistamines, narcotic analgesics, anesthetics, ethanol, and other drugs that themselves produce CNS depression. Zaleplon should not be taken with alcohol. Dosage adjustment may be necessary when zaleplon is administered with other CNS-depressant agents because of the potentially additive effects.
Severe anaphylactic and anaphylactoid reactions
What might happen if I take too much ZALEPLON?
Signs and symptoms of overdose effects of CNS depressants can be expected to present as exaggerations of the pharmacological effects noted in preclinical testing. Overdose is usually manifested by degrees of central nervous system depression ranging from drowsiness to coma. In mild cases, symptoms include drowsiness, mental confusion, and lethargy; in more serious cases, symptoms may include ataxia, hypotonia, hypotension, respiratory depression, rarely coma, and very rarely death.
Loss of consciousness, in addition to signs and symptoms consistent with CNS depressants as described above, have been reported following zaleplon overdose. Individuals have fully recovered from zaleplon overdoses of greater than 200 mg (10 times the maximum recommended dose of zaleplon). Rare instances of fatal outcomes following overdose with zaleplon, most often associated with overdose of additional CNS depressants, have been reported.
Recommended Treatment
Poison Control Center
How should I store and handle ZALEPLON?
Store at controlled room temperature 20° to 25°C (68° to 77°F) [see USP] .Zaleplon capsules 5 mg are opaque green cap and an opaque pale green body with cor over 322 on cap and body. They are supplied as follows:Bottles of 60 NDC 21695-376-60Zaleplon capsules 10 mg are opaque green cap and an opaque light green body with cor over 323 on cap and body. They are supplied as follows:Bottles of 14 NDC 21695-105-14Bottles of 30 NDC 21695-105-30Bottles of 60 NDC 21695-105-60 Zaleplon capsules 5 mg are opaque green cap and an opaque pale green body with cor over 322 on cap and body. They are supplied as follows:Bottles of 60 NDC 21695-376-60Zaleplon capsules 10 mg are opaque green cap and an opaque light green body with cor over 323 on cap and body. They are supplied as follows:Bottles of 14 NDC 21695-105-14Bottles of 30 NDC 21695-105-30Bottles of 60 NDC 21695-105-60 Zaleplon capsules 5 mg are opaque green cap and an opaque pale green body with cor over 322 on cap and body. They are supplied as follows:Bottles of 60 NDC 21695-376-60Zaleplon capsules 10 mg are opaque green cap and an opaque light green body with cor over 323 on cap and body. They are supplied as follows:Bottles of 14 NDC 21695-105-14Bottles of 30 NDC 21695-105-30Bottles of 60 NDC 21695-105-60 Zaleplon capsules 5 mg are opaque green cap and an opaque pale green body with cor over 322 on cap and body. They are supplied as follows:Bottles of 60 NDC 21695-376-60Zaleplon capsules 10 mg are opaque green cap and an opaque light green body with cor over 323 on cap and body. They are supplied as follows:Bottles of 14 NDC 21695-105-14Bottles of 30 NDC 21695-105-30Bottles of 60 NDC 21695-105-60
Clinical Information
Chemical Structure
No Image foundClinical Pharmacology
While zaleplon is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties, it interacts with the gamma-aminobutyric acid-benzodiazepine (GABA-BZ) receptor complex. Subunit modulation of the GABA-BZ receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in animal models.
Other nonclinical studies have also shown that zaleplon binds selectively to the brain omega-1 receptor situated on the alpha subunit of the GABA/chloride ion channel receptor complex and potentiates t-butyl-bicyclophosphorothionate (TBPS) binding. Studies of binding of zaleplon to recombinant GABA receptors (αβγ [omega-1] and αβγ [omega-2]) have shown that zaleplon has a low affinity for these receptors, with preferential binding to the omega-1 receptor.
Pharmacokinetics
The pharmacokinetics of zaleplon have been investigated in more than 500 healthy subjects (young and elderly), nursing mothers, and patients with hepatic disease or renal disease. In healthy subjects, the pharmacokinetic profile has been examined after single doses of up to 60 mg and once-daily administration at 15 mg and 30 mg for 10 days. Zaleplon was rapidly absorbed with a time to peak concentration (t) of approximately 1 hour and a terminal-phase elimination half-life (t) of approximately 1 hour. Zaleplon does not accumulate with once-daily administration and its pharmacokinetics are dose proportional in the therapeutic range.
Absorption
Zaleplon is rapidly and almost completely absorbed following oral administration. Peak plasma concentrations are attained within approximately 1 hour after oral administration. Although zaleplon is well absorbed, its absolute bioavailability is approximately 30% because it undergoes significant presystemic metabolism.
Distribution
Zaleplon is a lipophilic compound with a volume of distribution of approximately 1.4 L/kg following intravenous (IV) administration, indicating substantial distribution into extravascular tissues. The in vitro plasma protein binding is approximately 60%±15% and is independent of zaleplon concentration over the range of 10 ng/mL to 1000 ng/mL. This suggests that zaleplon disposition should not be sensitive to alterations in protein binding. The blood to plasma ratio for zaleplon is approximately 1, indicating that zaleplon is uniformly distributed throughout the blood with no extensive distribution into red blood cells.
Metabolism
After oral administration, zaleplon is extensively metabolized, with less than 1% of the dose excreted unchanged in urine. Zaleplon is primarily metabolized by aldehyde oxidase to form 5-oxo-zaleplon. Zaleplon is metabolized to a lesser extent by cytochrome P450 (CYP) 3A4 to form desethylzaleplon, which is quickly converted, presumably by aldehyde oxidase, to 5-oxo-desethylzaleplon. These oxidative metabolites are then converted to glucuronides and eliminated in urine. All of zaleplon's metabolites are pharmacologically inactive.
Elimination
After either oral or IV administration, zaleplon is rapidly eliminated with a mean t of approximately 1 hour. The oral-dose plasma clearance of zaleplon is about 3 L/h/kg and the IV zaleplon plasma clearance is approximately 1 L/h/kg. Assuming normal hepatic blood flow and negligible renal clearance of zaleplon, the estimated hepatic extraction ratio of zaleplon is approximately 0.7, indicating that zaleplon is subject to high first-pass metabolism.After administration of a radiolabeled dose of zaleplon, 70% of the administered dose is recovered in urine within 48 hours (71% recovered within 6 days), almost all as zaleplon metabolites and their glucuronides. An additional 17% is recovered in feces within 6 days, most as 5-oxo-zaleplon.
Effect of Food
In healthy adults a high-fat/heavy meal prolonged the absorption of zaleplon compared to the fasted state, delaying t by approximately 2 hours and reducing C by approximately 35%. Zaleplon AUC and elimination half-life were not significantly affected. These results suggest that the effects of zaleplon on sleep onset may be reduced if it is taken with or immediately after a high-fat/heavy meal.
Special Populations
Gender: There is no significant difference in the pharmacokinetics of zaleplon in men and women.
Race: The pharmacokinetics of zaleplon have been studied in Japanese subjects as representative of Asian populations. For this group, C and AUC were increased 37% and 64%, respectively. This finding can likely be attributed to differences in body weight, or alternatively, may represent differences in enzyme activities resulting from differences in diet, environment, or other factors. The effects of race on pharmacokinetic characteristics in other ethnic groups have not been well characterized.
Hepatic impairment: Zaleplon is metabolized primarily by the liver and undergoes significant presystemic metabolism. Consequently, the oral clearance of zaleplon was reduced by 70% and 87% in compensated and decompensated cirrhotic patients, respectively, leading to marked increases in mean C and AUC (up to 4-fold and 7-fold in compensated and decompensated patients, respectively), in comparison with healthy subjects. The dose of zaleplon should therefore be reduced in patients with mild to moderate hepatic impairment (see ). Zaleplon is not recommended for use in patients with severe hepatic impairment.
Renal impairment: Because renal excretion of unchanged zaleplon accounts for less than 1% of the administered dose, the pharmacokinetics of zaleplon are not altered in patients with renal insufficiency. No dose adjustment is necessary in patients with mild to moderate renal impairment. Zaleplon has not been adequately studied in patients with severe renal impairment.
Drug-Drug Interactions
Clinical Trials
Controlled Trials Supporting Effectiveness
Transient Insomnia
Chronic Insomnia
Adult outpatients with chronic insomnia were evaluated in six double-blind, parallel-group sleep laboratory studies that varied in duration from a single night up to 35 nights. Overall, these studies demonstrated a superiority of zaleplon 10 mg and 20 mg over placebo in reducing LPS on the first 2 nights of treatment. At later time points in 5-, 14-, and 28-night studies, a reduction in LPS from baseline was observed for all treatment groups, including the placebo group, and thus, a significant difference between zaleplon and placebo was not seen beyond 2 nights. In a 35-night study, zaleplon 10 mg was significantly more effective than placebo in reducing LPS at the primary efficacy endpoint on nights 29 and 30.
Elderly patients:Elderly outpatients with chronic insomnia were evaluated in two 2-week, double-blind, parallel-group outpatient studies that compared the effects of zaleplon 5 mg and 10 mg with placebo on a subjective measure of time to sleep onset (TSO). Zaleplon at both doses was superior to placebo on TSO, generally for the full duration of both studies, with an effect size generally similar to that seen in younger persons. The 10-mg dose tended to have a greater effect in reducing TSO.
Elderly outpatients with chronic insomnia were also evaluated in a 2-night sleep laboratory study involving doses of 5 mg and 10 mg. Both 5-mg and 10-mg doses of zaleplon were superior to placebo in reducing latency to persistent sleep (LPS).
Generally in these studies, there was a slight increase in sleep duration, compared to baseline, for all treatment groups, including placebo, and thus, a significant difference from placebo on sleep duration was not demonstrated.
Studies Pertinent to Safety Concerns for Sedative/Hypnotic Drugs
Memory Impairment
Sedative/Psychomotor Effects
Withdrawal-Emergent Anxiety and Insomnia
Zaleplon has a short half-life and no active metabolites. At the primary efficacy endpoint (nights 29 and 30) in a 35-night sleep laboratory study, polysomnographic recordings showed that wakefulness was not significantly longer with zaleplon than with placebo during the last quarter of the night. No increase in the signs of daytime anxiety was observed in clinical trials with zaleplon. In two sleep laboratory studies involving 14- and 28-nightly doses of zaleplon (5 mg and 10 mg in one study and 10 mg and 20 mg in the second) and structured assessments of daytime anxiety, no increases in daytime anxiety were detected. Similarly, in a pooled analysis (all the parallel-group, placebo-controlled studies) of spontaneously reported daytime anxiety, no difference was observed between zaleplon and placebo.
Rebound insomnia, defined as a dose-dependent temporary worsening in sleep parameters (latency, total sleep time, and number of awakenings) compared to baseline following discontinuation of treatment, is observed with short- and intermediate-acting hypnotics. Rebound insomnia following discontinuation of zaleplon relative to baseline was examined at both nights 1 and 2 following discontinuation in three sleep laboratory studies (14, 28, and 35 nights) and five outpatient studies utilizing patient diaries (14 and 28 nights). Overall, the data suggest that rebound insomnia may be dose dependent. At 20 mg, there appeared to be both objective (polysomnographic) and subjective (diary) evidence of rebound insomnia on the first night after discontinuation of treatment with zaleplon. At 5 mg and 10 mg, there was no objective and minimal subjective evidence of rebound insomnia on the first night after discontinuation of treatment with zaleplon. At all doses, the rebound effect appeared to resolve by the second night following withdrawal. In the 35-night study, there was a worsening in sleep on the first night off for both the 10-mg and 20-mg groups compared to placebo, but not to baseline. This discontinuation-emergent effect was mild, had the characteristics of the return of the symptoms of chronic insomnia, and appeared to resolve by the second night after zaleplon discontinuation.
Other Withdrawal-Emergent Phenomena
The potential for other withdrawal phenomena was also assessed in 14- to 28-night studies, including both the sleep laboratory studies and the outpatient studies, and in open-label studies of 6- and 12-month durations. The Benzodiazepine Withdrawal Symptom Questionnaire was used in several of these studies, both at baseline and then during days 1 and 2 following discontinuation. Withdrawal was operationally defined as the emergence of 3 or more new symptoms after discontinuation. Zaleplon was not distinguishable from placebo at doses of 5 mg, 10 mg, or 20 mg on this measure, nor was zaleplon distinguishable from placebo on spontaneously reported withdrawal-emergent adverse events. There were no instances of withdrawal delirium, withdrawal associated hallucinations, or any other manifestations of severe sedative/hypnotic withdrawal.
Non-Clinical Toxicology
Hypersensitivity to zaleplon or any excipients in the formulation (see also ).Because sleep disturbances may be the presenting manifestation of a physical and/or psychiatric disorder, symptomatic treatment of insomnia should be initiated only after a careful evaluation of the patient. Worsening of insomnia or the emergence of new thinking or behavior abnormalities may be the consequence of an unrecognized psychiatric or physical disorder. Such findings have emerged during the course of treatment with sedative/hypnotic drugs, including zaleplon. Because some of the important adverse effects of zaleplon appear to be dose-related, it is important to use the lowest possible effective dose, especially in the elderly (see ).
A variety of abnormal thinking and behavior changes have been reported to occur in association with the use of sedative/hypnotics. Some of these changes may be characterized by decreased inhibition (eg, aggressiveness and extroversion that seem out of character), similar to effects produced by alcohol and other CNS depressants. Other reported behavioral changes have included bizarre behavior, agitation, hallucinations, and depersonalization.
Abnormal Thinking and Behavioral Changes
It can rarely be determined with certainty whether a particular instance of the abnormal behaviors listed above is drug induced, spontaneous in origin, or a result of an underlying psychiatric or physical disorder. Nonetheless, the emergence of any new behavioral sign or symptom of concern requires careful and immediate evaluation. Following rapid dose decrease or abrupt discontinuation of the use of sedative/hypnotics, there have been reports of signs and symptoms similar to those associated with withdrawal from other CNS-depressant drugs (see ).
Zaleplon, like other hypnotics, has CNS-depressant effects.. Patients receiving zaleplon should be cautioned against engaging in hazardous occupations requiring complete mental alertness or motor coordination (eg, operating machinery or driving a motor vehicle) after ingesting the drug, including potential impairment of the performance of such activities that may occur the day following ingestion of zaleplon. Zaleplon, as well as other hypnotics, may produce additive CNS-depressant effects when coadministered with other psychotropic medications, anticonvulsants, antihistamines, narcotic analgesics, anesthetics, ethanol, and other drugs that themselves produce CNS depression. Zaleplon should not be taken with alcohol. Dosage adjustment may be necessary when zaleplon is administered with other CNS-depressant agents because of the potentially additive effects.
Severe anaphylactic and anaphylactoid reactions
Drug Interactions
CNS-Active Drugs
Imipramine: Coadministration of single doses of zaleplon 20 mg and imipramine 75 mg produced additive effects on decreased alertness and impaired psychomotor performance for 2 to 4 hours after administration. The interaction was pharmacodynamic with no alteration of the pharmacokinetics of either drug.
Paroxetine: Coadministration of a single dose of zaleplon 20 mg and paroxetine 20 mg daily for 7 days did not produce any interaction on psychomotor performance. Additionally, paroxetine did not alter the pharmacokinetics of zaleplon, reflecting the absence of a role of CYP2D6 in zaleplon's metabolism.
Thioridazine: Coadministration of single doses of zaleplon 20 mg and thioridazine 50 mg produced additive effects on decreased alertness and impaired psychomotor performance for 2 to 4 hours after administration. The interaction was pharmacodynamic with no alteration of the pharmacokinetics of either drug.
Venlafaxine: Coadministration of a single dose of zaleplon 10 mg and multiple doses of venlafaxine ER (extended release) 150 mg did not result in any significant changes in the pharmacokinetics of either zaleplon of venlafaxine. In addition, there was no pharmacodynamic interaction as a result of coadministration of zaleplon and venlafaxine ER.
Promethazine: Coadministration of a single dose of zaleplon and promethazine (10 and 25 mg, respectively) resulted in a 15% decrease in maximal plasma concentrations of zaleplon, but no change in the area under the plasma concentration-time curve. however, the pharmacodynamics of coadministration of zaleplon and promethazine have not been evaluated. Caution should be exercised when these 2 agents are coadministered.
Drugs That Induce CYP3A4Rifampin: CYP3A4 is ordinarily a minor metabolizing enzyme of zaleplon. Multiple-dose administration of the potent CYP3A4 inducer rifampin (600 mg every 24 hours, q24h, for 14 days), however, reduced zaleplon C and AUC by approximately 80%. The coadministration of a potent CYP3A4 enzyme inducer, although not posing a safety concern, thus could lead to ineffectiveness of zaleplon. An alternative non-CYP3A4 substrate hypnotic agent may be considered in patients taking CYP3A4 inducers such as rifampin, phenytoin, carbamazepine, and phenobarbital.
Drugs That Inhibit CYP3A4CYP3A4 is a minor metabolic pathway for the elimination of zaleplon because the sum of desethylzaleplon (formed via CYP3A4 in vitro) and its metabolites, 5-oxo-desethylzaleplon and 5-oxo-desethylzaleplon glucuronide, account for only 9% of the urinary recovery of a zaleplon dose. Coadministration of single, oral doses of zaleplon with erythromycin (10 mg and 800 mg respectively), a strong, selective CYP3A4 inhibitor, produced a 34% increase in zaleplon's maximal plasma concentrations and a 20% increase in the area under the plasma concentration-time curve. The magnitude of interaction with multiple doses of erythromycin is unknown. Other strong selective CYP3A4 inhibitors such as ketoconazole can also be expected to increase the exposure of zaleplon. A routine dosage adjustment of zaleplon is not considered necessary.
Drugs That Inhibit Aldehyde Oxidase
The aldehyde oxidase enzyme system is less well studied than the cytochrome P450 enzyme system. Diphenhydramine: Diphenhydramine is reported to be a weak inhibitor of aldehyde oxidase in rat liver, but its inhibitory effects in human liver are not known. There is no pharmacokinetic interaction between zaleplon and diphenhydramine following the administration of a single dose (10 mg and 50 mg, respectively) of each drug. However, because both of these compounds have CNS effects, an additive pharmacodynamic effect is possible.
Drugs That Inhibit Both Aldehyde Oxidase and CYP3A4
Cimetidine: Cimetidine inhibits both aldehyde oxidase (in vitro) and CYP3A4 (in vitro and in vivo), the primary and secondary enzymes, respectively, responsible for zaleplon metabolism. Concomitant administration of zaleplon (10 mg) and cimetidine (800 mg) produced an 85% increase in the mean Cmax and AUC of zaleplon. An initial dose of 5 mg should be given to patients who are concomitantly being treated with cimetidine (see ).
Drugs Highly Bound to Plasma Protein
Zaleplon is not highly bound to plasma proteins (fraction bound 60%±15%); therefore, the disposition of zaleplon is not expected to be sensitive to alterations in protein binding. In addition, administration of zaleplon to a patient taking another drug that is highly protein bound should not cause transient increase in free concentrations of the other drug.
Drugs with a Narrow Therapeutic Index Digoxin: zaleplon (10 mg) did not affect the pharmacokinetic or pharmacodynamic profile of digoxin (0.375 mg q24h for 8 days).Warfarin: Multiple oral doses of zaleplon (20 mg q24h for 13 days) did not affect the pharmacokinetics of warfarin (R+)- or (S-)-enantiomers or the pharmacodynamics (prothrombin time) following a single 25-mg oral dose of warfarin.
Drugs That Alter Renal ExcretionIbuprofen: Ibuprofen is known to affect renal function and, consequently, alter the renal excretion of other drugs. There was no apparent pharmacokinetic interaction between zaleplon and ibuprofen following single dose administration (10 mg and 600 mg, respectively) of each drug. This was expected because zaleplon is primarily metabolized and renal excretion of unchanged zaleplon accounts for less than 1% of the administered dose.
Timing of Drug Administration
Use in the elderly and/or debilitated patients
Use in patients with concomitant illness
The dose of zaleplon should be reduced to 5 mg in patients with mild to moderate hepatic impairment (see ). It is not recommended for use in patients with severe hepatic impairment.No dose adjustment is necessary in patients with mild to moderate renal impairment. Zaleplon has not been adequately studied in patients with severe renal impairment.
Use in patients with depression
The premarketing development program for zaleplon included zaleplon exposures in patients and/or normal subjects from 2 different groups of studies: approximately 900 normal subjects in clinical pharmacology/pharmacokinetic studies; and approximately 2,900 exposures from patients in placebo-controlled clinical effectiveness studies, corresponding to approximately 450 patient exposure years. The conditions and duration of treatment with zaleplon varied greatly and included (in overlapping categories) open-label and double-blind phases of studies, inpatients and outpatients, and short-term or longer-term exposure. Adverse reactions were assessed by collecting adverse events, results of physical examinations, vital signs, weights, laboratory analyses, and ECGs.
Adverse events during exposure were obtained primarily by general inquiry and recorded by clinical investigators using terminology of their own choosing. Consequently, it is not possible to provide a meaningful estimate of the proportion of individuals experiencing adverse events without first grouping similar types of events into a smaller number of standardized event categories. In the tables and tabulations that follow, COSTART terminology has been used to classify reported adverse events.
The stated frequencies of adverse events represent the proportion of individuals who experienced, at least once, a treatment-emergent adverse event of the type listed. An event was considered treatment-emergent if it occurred for the first time or worsened while receiving therapy following baseline evaluation.
Adverse Findings Observed in Short-Term, Placebo-Controlled Trials
Adverse Events Associated With Discontinuation of Treatment
Adverse Events Occurring at an Incidence of 1% or More Among Zaleplon 20 mg-Treated Patients
The prescriber should be aware that these figures cannot be used to predict the incidence of adverse events in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and non-drug factors to the adverse event incidence rate in the population studied.
1: Events for which the incidence for zaleplon 20 mg-treated patients was at least 1% and greater than the incidence among placebo-treated patients. Incidence greater than 1% has been rounded to the nearest whole number.
Other Adverse Events Observed During the Premarketing Evaluation of Zaleplon
Events are further categorized by body system and listed in order of decreasing frequency according to the following definitions: adverse events are those occurring on one or more occasions in at least 1/100 patients; adverse events are those occurring in less than 1/100 patients but at least 1/1,000 patients; events are those occurring in fewer than 1/1,000 patients.
Body as a whole
Frequent
Infrequent
Cardiovascular system
Frequent
Infrequent
Digestive system
Frequent
Infrequent
Endocrine system
Rare
Hemic and lymphatic system
Infrequent
Rare
Metabolic and nutritional
Infrequent
Rare
Musculoskeletal system
Frequent
Infrequent
Rare
Nervous system
Frequent
Rare
Respiratory System
Frequent
Infrequent
Rare
Skin and Appendages
Frequent
Infrequent
Rare
Special senses
Frequent
Infrequent
Rare
Urogenital
Infrequent
Rare
Postmarketing Reports
Reference
This information is obtained from the National Institute of Health's Standard Packaging Label drug database.
"https://dailymed.nlm.nih.gov/dailymed/"
While we update our database periodically, we cannot guarantee it is always updated to the latest version.
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Clonazepam Description Each single-scored tablet, for oral administration, contains 0.5 mg, 1 mg, or 2 mg Clonazepam, USP, a benzodiazepine. Each tablet also contains corn starch, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and povidone. Clonazepam tablets USP 0.5 mg contain Yellow D&C No. 10 Aluminum Lake. Clonazepam tablets USP 1 mg contain Yellow D&C No. 10 Aluminum Lake, as well as FD&C Blue No. 1 Aluminum Lake. Chemically, Clonazepam, USP is 5-(o-chlorophenyl)-1,3-dihydro-7-nitro-2H-1,4-benzodiazepin-2-one. It is a light yellow crystalline powder. It has the following structural formula: C15H10ClN3O3 M.W. 315.72Tips
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Interactions
Interactions
A total of 440 drugs (1549 brand and generic names) are known to interact with Imbruvica (ibrutinib). 228 major drug interactions (854 brand and generic names) 210 moderate drug interactions (691 brand and generic names) 2 minor drug interactions (4 brand and generic names) Show all medications in the database that may interact with Imbruvica (ibrutinib).