Alzheimer disease:
Oral:
Mild to moderate: Initial: 5 mg once daily; may increase to 10 mg once daily after 4 to 6 weeks (Ref).
Moderate to severe: Initial: 5 mg once daily; may increase to 10 mg once daily after 4 to 6 weeks; may increase further to 23 mg once daily if stable on 10 mg daily for ≥3 months (Ref).
Note: Doses of 23 mg/day may be associated with a limited increase in efficacy compared to 10 mg/day and with increased adverse effects (Ref).
Transdermal: Initial: 5 mg per 24-hour patch applied once weekly; may increase to 10 mg per 24-hour patch applied once weekly after 4 to 6 weeks (maximum: 10 mg per 24 hours).
Missed dose: If a patch falls off or a dose is missed, apply a new patch immediately and then replace this patch 7 days later to start a new one-week cycle.
Dementia (ie, Parkinson disease dementia, dementia with Lewy bodies, comorbid vascular dementia) (off-label use): Oral: Initial: 5 mg once daily; may increase to 10 mg once daily after 4 to 6 weeks (Ref).
Transitioning from oral to transdermal: Patients being treated with a total oral daily dose of 5 mg may be switched to 5 mg per 24-hour patch applied once weekly. Patients being treated with a total oral daily dose of 5 mg for at least 4 to 6 weeks may be increased to a 10 mg per 24-hour patch applied once weekly. Patients being treated with a total oral daily dose of 10 mg may be switched to the 10 mg per 24-hour patch applied once weekly.
Discontinuation of therapy: Discontinuation of therapy may result in worsening of cognitive function (Ref). Avoid abrupt discontinuation except in the case of severe adverse drug reaction to minimize withdrawal symptoms (eg, altered mental status, hallucinations, delusions, insomnia, increased anxiety and agitation). In general, cholinesterase inhibitors should be tapered using a 50% dose reduction or stepwise reduction via available dose formulations every 4 weeks to the lowest dose prior to discontinuation. Consider re-initiation if clear worsening of the condition occurs after withdrawal (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason A. Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Altered kidney function: Oral, transdermal: Mild to severe impairment: No dosage adjustment necessary (Ref).
Hemodialysis, intermittent (thrice weekly): Oral, transdermal: Unlikely to be dialyzed (highly protein bound): No supplemental dose or dosage adjustment necessary (Ref). One small case series in hemodialysis patients reported efficacy and tolerability using an initial oral dose of 2.5 mg/day titrated to 5 mg/day after 1 month (Ref).
Peritoneal dialysis: Oral, transdermal: Unlikely to be dialyzed (highly protein bound): No supplemental dose or dosage adjustment necessary (Ref).
There are no dosage adjustments provided in the manufacturer’s labeling.
Refer to adult dosing. Note: The Canadian labeling recommends a maximum dose of 5 mg once daily in elderly women (≥85 years of age) of low body weight.
Acetylcholinesterase inhibitors, including donepezil, have been associated with cardiovascular effects, such as conduction abnormalities (eg, bradycardia, atrioventricular block, arrhythmias [including prolonged QT interval on ECG and torsades de pointes]) and hypertension (Ref). Syncope has also been reported (Ref).
Mechanism: Related to the mechanism of action; increased cholinergic activity results in vagotonic effects (Ref).
Onset: Delayed; reported months to years after initiation (Ref).
Risk factors:
• Older adults (Ref)
• History of cardiovascular disease (Ref)
• History of cardiac conduction abnormalities or sick sinus syndrome (Ref)
• History of stroke or transient ischemic attack, diabetes, or syncope (Ref)
• Concurrent medications for cardiovascular and/or cerebrovascular disease (Ref)
GI effects are the most common adverse reactions associated with donepezil; symptoms may include nausea, vomiting, and diarrhea (Ref). Decreased appetite, weight loss, and/or anorexia may also occur (Ref). GI effects are typically transient and self-limiting with resolution within 1 to 3 weeks of initiation.
Mechanism: Dose-related; related to mechanism of action. Increased cholinergic activity increases smooth muscle contraction, peristalsis, and sphincter relaxation in the GI tract, leading to GI effects (Ref).
Onset: Varied; nausea/vomiting/diarrhea most commonly occurred within the first 4 to 6 weeks of treatment (Ref).
Risk factors:
• Higher doses (≥10 mg/day) (Ref)
• Dose initiation or titration
• Patients weighing <55 kg
• Concurrent medications for cardiovascular and/or cerebrovascular disease (Ref)
The following adverse drug reactions and incidences are derived from product labeling for oral formulations unless otherwise specified. Adverse reactions reported in adults.
>10%:
Gastrointestinal: Diarrhea (5% to 15%) (table 1) , nausea (3% to 19%) (table 2)
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
Comments |
---|---|---|---|---|---|---|
15% |
5% |
10 mg/day |
Mild to moderate Alzheimer disease |
315 |
315 |
One-week titration |
10% |
5% |
5 mg/day or 10 mg/day |
Mild to moderate Alzheimer disease |
747 |
355 |
N/A |
8% |
5% |
5 mg/day |
Mild to moderate Alzheimer disease |
311 |
315 |
No titration |
8% |
N/A |
23 mg/day |
Moderate to severe Alzheimer disease |
963 |
N/A |
N/A |
5% |
N/A |
10 mg/day |
Moderate to severe Alzheimer disease |
471 |
N/A |
N/A |
10% |
4% |
5 mg/day or 10 mg/day |
Severe Alzheimer disease |
501 |
392 |
N/A |
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
Comments |
---|---|---|---|---|---|---|
19% |
6% |
10 mg/day |
Mild to moderate Alzheimer disease |
315 |
315 |
One-week titration |
11% |
6% |
5 mg/day or 10 mg/day |
Mild to moderate Alzheimer disease |
747 |
355 |
N/A |
5% |
6% |
5 mg/day |
Mild to moderate Alzheimer disease |
311 |
315 |
No titration |
12% |
N/A |
23 mg/day |
Moderate to severe Alzheimer disease |
963 |
N/A |
N/A |
3% |
N/A |
10 mg/day |
Moderate to severe Alzheimer disease |
471 |
N/A |
N/A |
6% |
2% |
5 mg/day or 10 mg/day |
Severe Alzheimer disease |
501 |
392 |
N/A |
Local: Application-site reaction (transdermal: including application-site dermatitis, application-site edema [<1%], application-site erythema [65%], application-site pain, application-site pruritus, papule of skin [16%: application-site])
Nervous system: Insomnia (2% to 14%)
Miscellaneous: Accidental injury (7% to 13%)
1% to 10%:
Cardiovascular: Chest pain (2%), hypertension (3%) (table 3) , syncope (2%) (table 4)
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
---|---|---|---|---|---|
3% |
2% |
5 mg/day or 10 mg/day |
Severe Alzheimer disease |
501 |
392 |
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
---|---|---|---|---|---|
2% |
1% |
5 mg/day or 10 mg/day |
Mild to moderate Alzheimer disease |
747 |
355 |
2% |
1% |
5 mg/day or 10 mg/day |
Severe Alzheimer disease |
501 |
392 |
Dermatologic: Ecchymoses (4% to 5%), eczema (3%)
Endocrine & metabolic: Hyperlipidemia (2%), weight loss (3% to 5%) (table 5)
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
---|---|---|---|---|---|
3% |
1% |
5 mg/day or 10 mg/day |
Mild to moderate Alzheimer disease |
747 |
355 |
5% |
N/A |
23 mg/day |
Moderate to severe Alzheimer disease |
963 |
N/A |
3% |
N/A |
10 mg/day |
Moderate to severe Alzheimer disease |
471 |
N/A |
Gastrointestinal: Anorexia (2% to 8%) (table 6) , gastrointestinal hemorrhage (1%), vomiting (3% to 9%) (table 7)
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
Comments |
---|---|---|---|---|---|---|
7% |
2% |
10 mg/day |
Mild to moderate Alzheimer disease |
315 |
315 |
One-week titration |
4% |
2% |
5 mg/day or 10 mg/day |
Mild to moderate Alzheimer disease |
747 |
355 |
N/A |
3% |
2% |
5 mg/day |
Mild to moderate Alzheimer disease |
311 |
315 |
No titration |
5% |
N/A |
23 mg/day |
Moderate to severe Alzheimer disease |
963 |
N/A |
N/A |
2% |
N/A |
10 mg/day |
Moderate to severe Alzheimer disease |
471 |
N/A |
N/A |
8% |
4% |
5 mg/day or 10 mg/day |
Severe Alzheimer disease |
501 |
392 |
N/A |
Drug (Donepezil) |
Placebo |
Dose |
Indication |
Number of Patients (Donepezil) |
Number of Patients (Placebo) |
Comments |
---|---|---|---|---|---|---|
8% |
3% |
10 mg/day |
Mild to moderate Alzheimer disease |
315 |
315 |
One-week titration |
5% |
3% |
5 mg/day or 10 mg/day |
Mild to moderate Alzheimer disease |
747 |
355 |
N/A |
3% |
3% |
5 mg/day |
Mild to moderate Alzheimer disease |
311 |
315 |
No titration |
9% |
N/A |
23 mg/day |
Moderate to severe Alzheimer disease |
963 |
N/A |
N/A |
3% |
N/A |
10 mg/day |
Moderate to severe Alzheimer disease |
471 |
N/A |
N/A |
8% |
4% |
5 mg/day or 10 mg/day |
Severe Alzheimer disease |
501 |
392 |
N/A |
Genitourinary: Urinary frequency (2%), urinary incontinence (1% to 3%)
Hematologic & oncologic: Bruise (2%), hemorrhage (2%)
Nervous system: Abnormal dreams (3%), asthenia (1% to 2%), confusion (2%), depression (2% to 3%), dizziness (2% to 8%), drowsiness (1% to 2%), emotional lability (2%), fatigue (1% to 8%), hallucination (3%), headache (3% to 10%), hostility (3%), nervousness (3%), pain (3% to 9%), personality disorder (2%)
Neuromuscular & skeletal: Arthritis (2%), back pain (3%), increased creatine phosphokinase in blood specimen (3%), muscle cramps (6% to 8%)
Miscellaneous: Fever (2%)
<1%: Gastrointestinal: Peptic ulcer
Postmarketing (any formulation):
Cardiovascular: Atrioventricular block (Ref), bradycardia (Ref), prolonged QT interval on ECG (Ref), torsades de pointes (Ref)
Dermatologic: Skin rash (Ref)
Endocrine & metabolic: Hyponatremia (Ref)
Gastrointestinal: Cholecystitis, pancreatitis (Ref)
Hematologic & oncologic: Hemolytic anemia
Hepatic: Hepatitis (Ref)
Nervous system: Aggressive behavior, agitation (Ref), neuroleptic malignant syndrome (Ref), seizure (Ref)
Neuromuscular & skeletal: Rhabdomyolysis (Ref)
Hypersensitivity to donepezil, piperidine derivatives, or any component of the formulation; patients with a history of contact dermatitis with the use of transdermal donepezil (transdermal).
Canadian labeling: Additional contraindications (not in US labeling): History of QT prolongation and/or torsades de pointes, including congenital long QT syndromes; history of cardiac arrhythmias.
Concerns related to adverse effects:
• Rhabdomyolysis: Rare cases of rhabdomyolysis (including acute renal failure) have been reported after a few months of therapy (Sahin 2014) or in the days following therapy initiation and dose increase (Aricept Canadian product monograph 2024). Use with caution in patients with risk factors for rhabdomyolysis (eg, concomitant medications associated with rhabdomyolysis, history of muscular disorders, uncontrolled hypothyroidism, renal/hepatic impairment). Discontinuation of therapy may be necessary for marked elevation of CPK levels and/or symptoms (eg, muscle pain, tenderness or weakness, malaise, fever, dark urine) suggesting rhabdomyolysis.
Disease-related concerns:
• Peptic ulcer disease: Use with caution in patients at risk of ulcer disease (eg, previous history or NSAID use); cholinesterase inhibitors may increase gastric acid secretion. Monitor for symptoms of bleeding.
• Respiratory disease: Use with caution in patients with chronic obstructive pulmonary disease and/or asthma.
• Seizure disorder: Use with caution in patients with a history of seizure disorder; cholinomimetics may potentially cause generalized seizures, although seizure activity may also result from Alzheimer disease.
• Urinary tract obstruction: Use with caution in patients with bladder outlet obstruction; cholinomimetics may cause or worsen outflow obstructions.
Dosage form specific issues:
• Aspartame: Some products may contain aspartame, which is metabolized to phenylalanine and must be avoided (or used with caution) in patients with phenylketonuria.
• Transdermal: Application-site reactions have been reported, which may lead to contact dermatitis; discontinue therapy if an intense local reaction occurs (eg, increasing erythema, edema, papules, vesicles) and if symptoms do not improve after 48 hours of patch removal.
Special populations:
• Bariatric surgery: Presurgical assessment of the indication for use, symptoms, and goals of therapy should be documented to enable postsurgical assessment. Monitor for continued efficacy and tolerability after bariatric surgery and consider switching to an alternative medication if symptoms worsen.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Patch Weekly, Transdermal, as hydrochloride:
Adlarity: 5 mg/day (1 ea, 4 ea); 10 mg/day (1 ea, 4 ea)
Tablet, Oral, as hydrochloride:
Aricept: 5 mg, 10 mg, 23 mg
Generic: 5 mg, 10 mg, 23 mg
Tablet Disintegrating, Oral, as hydrochloride:
Generic: 5 mg, 10 mg
May be product dependent
Patch weekly (Adlarity Transdermal)
5 mg/day (per each): $135.00
10 mg/day (per each): $135.00
Tablet, orally-disintegrating (Donepezil HCl Oral)
5 mg (per each): $7.79
10 mg (per each): $7.79
Tablets (Aricept Oral)
5 mg (per each): $20.24
10 mg (per each): $20.24
23 mg (per each): $18.10
Tablets (Donepezil HCl Oral)
5 mg (per each): $0.18 - $8.67
10 mg (per each): $0.18 - $8.67
23 mg (per each): $10.41 - $11.36
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Tablet, Oral, as hydrochloride:
Aricept: 5 mg, 10 mg
Generic: 5 mg, 10 mg
Tablet Disintegrating, Oral, as hydrochloride:
Aricept RDT: 5 mg [DSC], 10 mg [DSC]
Generic: 5 mg [DSC], 10 mg [DSC]
Oral: Administer at bedtime without regard to food.
Aricept 23 mg tablet: Swallow whole with water; do NOT crush or chew due to an increased rate of absorption. The 23 mg strength is provided in a unique film-coated formulation different from the 5 mg or 10 mg tablet strengths, which results in an altered pharmacokinetic profile.
Aricept ODT: Allow tablet to dissolve completely on tongue and follow with water.
Transdermal: Allow patch pouch to reach room temperature prior to removing from packaging for application; do not use external heat sources to warm. Use within 24 hours of removing from the refrigerator; do not apply a cold patch. Patches should be applied weekly to a clean, hairless area of the back avoiding the spine (preferred), upper buttocks, or upper outer thigh; avoid a location that may be rubbed by tight clothing. Press firmly for 30 seconds to ensure proper adherence. Do not apply to red, irritated, or cut skin or an area where medication, cream, lotion, or powder has been applied. Do not shave the site. Rotate patch sites weekly; do not use the same site for at least 14 days. May bathe while wearing patch. Avoid long exposure to external heat sources (eg, excessive sunlight, heating pads, saunas, solariums). Dispose of any used patches by folding adhesive ends together and discard properly in trash away from children and pets; do not flush down the toilet.
Alzheimer disease: Treatment of mild, moderate, or severe dementia of the Alzheimer type.
Dementia (ie, Parkinson disease dementia, dementia with Lewy bodies, comorbid vascular dementia)
Aricept may be confused with AcipHex, Ascriptin, and Azilect
Donepezil is identified in the Screening Tool of Older Person's Prescriptions (STOPP) criteria as a potentially inappropriate medication in older adults (≥65 years of age) with a history of persistent bradycardia, heart block, or recurring syncope with an unknown cause (O’Mahony 2023).
Substrate of CYP2D6 (Minor), CYP3A4 (Minor); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits Acetylcholinesterase;
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Agents with Clinically Relevant Anticholinergic Effects: Acetylcholinesterase Inhibitors may decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Acetylcholinesterase Inhibitors. Risk C: Monitor
Amifampridine: Acetylcholinesterase Inhibitors may increase therapeutic effects of Amifampridine. Amifampridine side effects may also be increased. Amifampridine may increase therapeutic effects of Acetylcholinesterase Inhibitors. Acetylcholinesterase inhibitor side effects may also be increased. Risk C: Monitor
Antipsychotic Agents: Donepezil may increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
Benoxinate: Acetylcholinesterase Inhibitors may increase therapeutic effects of Benoxinate. Specifically, the effects of benoxinate may be prolonged. Risk C: Monitor
Beta-Blockers: Acetylcholinesterase Inhibitors may increase bradycardic effects of Beta-Blockers. Risk C: Monitor
Bradycardia-Causing Agents: May increase bradycardic effects of Bradycardia-Causing Agents. Risk C: Monitor
Ceritinib: Bradycardia-Causing Agents may increase bradycardic effects of Ceritinib. Management: If this combination cannot be avoided, monitor patients for evidence of symptomatic bradycardia, and closely monitor blood pressure and heart rate during therapy. Risk D: Consider Therapy Modification
Chlorprothixene: Acetylcholinesterase Inhibitors may increase adverse/toxic effects of Chlorprothixene. Acetylcholinesterase Inhibitors may increase therapeutic effects of Chlorprothixene. Risk C: Monitor
Cholinergic Agonists: Acetylcholinesterase Inhibitors may increase adverse/toxic effects of Cholinergic Agonists. Specifically, cholinergic effects may be enhanced or increased. Risk C: Monitor
Corticosteroids (Systemic): May increase adverse/toxic effects of Acetylcholinesterase Inhibitors. Increased muscular weakness may occur. Risk C: Monitor
Dipyridamole: May decrease therapeutic effects of Acetylcholinesterase Inhibitors. Risk C: Monitor
Etrasimod: May increase bradycardic effects of Bradycardia-Causing Agents. Risk C: Monitor
Fexinidazole: Bradycardia-Causing Agents may increase arrhythmogenic effects of Fexinidazole. Risk X: Avoid
Fingolimod: Bradycardia-Causing Agents may increase bradycardic effects of Fingolimod. Management: Consult with the prescriber of any bradycardia-causing agent to see if the agent could be switched to an agent that does not cause bradycardia prior to initiating fingolimod. If combined, perform continuous ECG monitoring after the first fingolimod dose. Risk D: Consider Therapy Modification
Gepotidacin: May increase therapeutic effects of Acetylcholinesterase Inhibitors. Risk C: Monitor
Haloperidol: QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of Haloperidol. Risk C: Monitor
Ivabradine: Bradycardia-Causing Agents may increase bradycardic effects of Ivabradine. Risk C: Monitor
Lacosamide: Bradycardia-Causing Agents may increase AV-blocking effects of Lacosamide. Risk C: Monitor
Landiolol: Bradycardia-Causing Agents may increase bradycardic effects of Landiolol. Risk X: Avoid
Midodrine: May increase bradycardic effects of Bradycardia-Causing Agents. Risk C: Monitor
Neuromuscular-Blocking Agents (Nondepolarizing): Acetylcholinesterase Inhibitors may decrease neuromuscular-blocking effects of Neuromuscular-Blocking Agents (Nondepolarizing). Risk C: Monitor
Ozanimod: May increase bradycardic effects of Bradycardia-Causing Agents. Risk C: Monitor
Ponesimod: Bradycardia-Causing Agents may increase bradycardic effects of Ponesimod. Management: Avoid coadministration of ponesimod with drugs that may cause bradycardia when possible. If combined, monitor heart rate closely and consider obtaining a cardiology consult. Do not initiate ponesimod in patients on beta-blockers if HR is less than 55 bpm. Risk D: Consider Therapy Modification
QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Siponimod: Bradycardia-Causing Agents may increase bradycardic effects of Siponimod. Management: Avoid coadministration of siponimod with drugs that may cause bradycardia. If combined, consider obtaining a cardiology consult regarding patient monitoring. Risk D: Consider Therapy Modification
Succinylcholine: Acetylcholinesterase Inhibitors may increase neuromuscular-blocking effects of Succinylcholine. Risk C: Monitor
Adverse events have been observed in some animal reproduction studies.
It is not known if donepezil is present in breast milk.
According to the manufacturer, the decision to breastfeed during therapy should consider the risk of infant exposure, the benefits of breastfeeding to the infant, and benefits of treatment to the mother.
Mental status, weight, symptoms of GI intolerance, symptoms of active or occult GI bleeding.
Alzheimer's disease is characterized by cholinergic deficiency in the cortex and basal forebrain, which contributes to cognitive deficits. Donepezil reversibly and noncompetitively inhibits centrally active acetylcholinesterase, the enzyme responsible for hydrolysis of acetylcholine. This appears to result in increased concentrations of acetylcholine available for synaptic transmission in the CNS.
Absorption: Oral: Well absorbed; Transdermal: Delayed.
Distribution: Vdss: 12 to 16 L/kg.
Protein binding: ~96%, primarily to albumin (75%) and alpha1-acid glycoprotein (21%).
Metabolism: Extensive hepatic metabolism via CYP2D6 and 3A4 and glucuronidation to four major metabolites (two are active).
Half-life elimination: Oral: 70 hours; time to steady-state: 15 days; Transdermal: ~91 hours.
Time to peak, plasma: Tablet, 10 mg: 3 hours; Tablet, 23 mg: ~8 hours; Transdermal: ~7 days; Note: Peak plasma concentrations almost twofold higher for the 23 mg tablet compared to the 10 mg tablet.
Excretion: Urine (57%; 17% as unchanged drug); feces (15%)
Hepatic function impairment: Clearance decreased 20% in patients with stable alcoholic cirrhosis.
Older adult: Clearance decreases with increasing age. When compared with patients 65 years of age, 90-year-old patients have a 17% decrease in clearance, while 40-year-old patients have a 33% increase in clearance; effect may not be clinically significant.
Body weight: For body weight from 50 to 110 kg, clearance increased from 7.77 to 14.04 L/hour, with a value of 10 L/hour for 70 kg individuals.
CYP2D6 genotype: When compared with CYP2D6 extensive metabolizers, poor metabolizers had a 31.5% slower clearance and ultra-rapid metabolizers had a 24% faster clearance.
Transdermal: AUC and Cmax were 14% to 18% lower and 21% to 24% higher, respectively, when applied to the thigh and buttocks compared to the back. Exposure was increased temporarily by up to 60% when application site was exposed to heat.