Logo

OpiCalc

FavoritesSpecialtiesDrugsGuidelinesMost Used

Quick Access

Favorites
Most Used

All Specialties

OpiCalc Logo
Clinical CalculatorsDrugsGuidelines
SpecsDrugsGuides
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
OpiCalc Logo

OpiCalc

Easy, fast, and private medical tools for clinicians. Always free.

No Login Required
Ready for the Bedside

Resources

About UsEditorial PolicyMedical DisclaimerPrivacy PolicyTerms of UseCookie Policy

Support

Contact Us

Clinical Notice:OpiCalc is not a substitute for professional clinical judgment. Always verify dosages and guidelines.

OpiCalc © 2018-2026

•

All Rights Reserved

Registry Hub
Peer-Reviewed Evidence
HomeDrug RegistryCompareABILIFY MAINTENA KIT vs ACETAMINOPHEN CAFFEINE AND DIHYDROCODEINE BITARTRATE
Comparative Pharmacology

ABILIFY MAINTENA KIT vs ACETAMINOPHEN CAFFEINE AND DIHYDROCODEINE BITARTRATE Comparison

Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.

Clinical EssentialsPharmacokineticsSpecial PopulationsSafety & MonitoringPregnancy & LactationClinical Insights
Differential Analysis

ABILIFY MAINTENA KIT vs ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.

View ABILIFY MAINTENA KIT Monograph View ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE Monograph
ABILIFY MAINTENA KIT
Atypical antipsychotic
Category C
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Opioid Agonist
Category D/X
TL;DR — Key Differences
  • Drug class: ABILIFY MAINTENA KIT is a Atypical antipsychotic; ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE is a Opioid Agonist.
  • Half-life: ABILIFY MAINTENA KIT has a half-life of Aripiprazole: 75-146 hours; dehydro-aripiprazole: 94-146 hours. Long half-life allows monthly intramuscular dosing.; ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE has Acetaminophen: 2-3 hours (normal), prolonged in hepatic impairment. Caffeine: 3-6 hours (adults), prolonged in liver disease or with oral contraceptives. Dihydrocodeine: 3.5-6 hours (terminal). Clinical context: q6h dosing interval appropriate; accumulation risk in renal/hepatic impairment..
  • No direct drug-drug interaction has been documented between ABILIFY MAINTENA KIT and ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE.
  • Pregnancy: ABILIFY MAINTENA KIT is rated Category C; ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE is rated Category D/X.

Last clinically reviewed: July 2026 · OpiCalc Medical Review Team

Clinical Essentials

ABILIFY MAINTENA KIT
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Mechanism of Action
ABILIFY MAINTENA KIT

Aripiprazole is a partial agonist at D2 and 5-HT1A receptors and an antagonist at 5-HT2A receptors, stabilizing dopamine and serotonin activity.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: inhibits cyclooxygenase (COX) activity, reducing prostaglandin synthesis; analgesic and antipyretic. Caffeine: adenosine receptor antagonist; enhances analgesic effect. Dihydrocodeine: mu-opioid receptor agonist; produces analgesia via central opioid receptors.

Indications
ABILIFY MAINTENA KIT

Treatment of schizophrenia,Maintenance monotherapy for bipolar I disorder,Adjunctive treatment of major depressive disorder (off-label),Irritability associated with autistic disorder (off-label),Tourette's disorder (off-label)

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Management of mild to moderate pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate,Off-label: acute pain, chronic pain

Standard Dosing
ABILIFY MAINTENA KIT

400 mg IM once monthly after establishing tolerability with oral aripiprazole.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

1-2 tablets (each containing acetaminophen 300 mg, caffeine 30 mg, dihydrocodeine bitartrate 20 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.

Direct Interaction
ABILIFY MAINTENA KIT
No Direct Interaction
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
No Direct Interaction

Pharmacokinetics

ABILIFY MAINTENA KIT
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Half-Life
ABILIFY MAINTENA KIT

Aripiprazole: 75-146 hours; dehydro-aripiprazole: 94-146 hours. Long half-life allows monthly intramuscular dosing.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: 2-3 hours (normal), prolonged in hepatic impairment. Caffeine: 3-6 hours (adults), prolonged in liver disease or with oral contraceptives. Dihydrocodeine: 3.5-6 hours (terminal). Clinical context: q6h dosing interval appropriate; accumulation risk in renal/hepatic impairment.

Metabolism
ABILIFY MAINTENA KIT

Primarily hepatic via CYP2D6 and CYP3A4; active metabolite dehydro-aripiprazole.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: primarily hepatic via glucuronidation and sulfation; minor CYP2E1, CYP1A2, CYP3A4. Caffeine: hepatic via CYP1A2. Dihydrocodeine: O-demethylation to dihydromorphine via CYP2D6; also via CYP3A4.

Excretion
ABILIFY MAINTENA KIT

Renal (approximately 25% unchanged and 55% as metabolites); fecal (approximately 20% as metabolites).

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: renal excretion of metabolites (glucuronide 60%, sulfate 30%, cysteine/mercapturate 8%), <5% unchanged. Caffeine: renal excretion of metabolites (1-methyluric acid, 1-methylxanthine, etc.), <2% unchanged. Dihydrocodeine: renal excretion of metabolites (dihydrocodeine-6-glucuronide, nordihydrocodeine, dihydromorphine), ~20% unchanged. Overall, predominantly renal (≥85%), minor biliary/fecal.

Protein Binding
ABILIFY MAINTENA KIT

Aripiprazole is >99% bound to serum albumin and alpha-1-acid glycoprotein.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: 10-25% (albumin). Caffeine: 25-36% (albumin). Dihydrocodeine: ~20-30% (albumin and α1-acid glycoprotein).

VD (L/kg)
ABILIFY MAINTENA KIT

Aripiprazole: 4.9 L/kg (range 3.7-7.2 L/kg), indicating extensive tissue distribution.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: 0.7-1.0 L/kg. Caffeine: 0.5-0.8 L/kg. Dihydrocodeine: 1.0-1.5 L/kg. Clinical meaning: moderate distribution, potential for central nervous system penetration.

Bioavailability
ABILIFY MAINTENA KIT

IM (Abilify Maintena): 100% relative to oral aripiprazole after 5 monthly doses; oral: 87%.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: oral 75-85%. Caffeine: oral ~100%. Dihydrocodeine: oral ~20-30% (first-pass metabolism; extended-release formulations have altered bioavailability).

Special Populations

ABILIFY MAINTENA KIT
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Renal Adjustments
ABILIFY MAINTENA KIT

No adjustment for mild/moderate impairment; caution in severe impairment (Cr Cl <30 m L/min).

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

GFR 30-50 m L/min: administer every 6 hours; GFR 10-30 m L/min: administer every 8 hours; GFR <10 m L/min: administer every 12 hours; avoid in severe impairment due to dihydrocodeine accumulation.

Hepatic Adjustments
ABILIFY MAINTENA KIT

No adjustment for mild impairment; moderate to severe (Child-Pugh class B or C): reduce dose to 300 mg/month.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% or extend interval to every 8 hours; Child-Pugh C: avoid use due to acetaminophen hepatotoxicity and dihydrocodeine accumulation.

Pediatric Dosing
ABILIFY MAINTENA KIT

Not approved for pediatric use.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Not recommended for children under 12 years due to dihydrocodeine risks; for adolescents 12-18 years: 1 tablet orally every 4-6 hours as needed, maximum 4 tablets per day (weight-based dosing not established).

Geriatric Dosing
ABILIFY MAINTENA KIT

Use cautiously due to increased sensitivity; consider lower doses and monitor for adverse effects.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Initiate with 1 tablet orally every 6 hours; caution due to increased sensitivity to opioids and hepatotoxicity from acetaminophen; maximum 4 tablets per day; monitor renal and hepatic function.

Safety & Monitoring

ABILIFY MAINTENA KIT
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Black Box Warnings
ABILIFY MAINTENA KIT
FDA Black Box Warning

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
FDA Black Box Warning

Risk of addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of acetaminophen can cause fatal hepatotoxicity; concomitant use with benzodiazepines or CNS depressants may cause profound sedation, respiratory depression, coma, and death; neonatal opioid withdrawal syndrome with prolonged use during pregnancy.

Warnings/Precautions
ABILIFY MAINTENA KIT

Increased mortality in elderly dementia patients; suicidal thoughts and behaviors; neuroleptic malignant syndrome; tardive dyskinesia; metabolic changes (hyperglycemia, dyslipidemia, weight gain); orthostatic hypotension; leukopenia/neutropenia; seizure risk; dysphagia; body temperature dysregulation; pathological gambling and other impulse control disorders.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Addiction, abuse, and misuse; respiratory depression; acetaminophen hepatotoxicity; drug interaction with benzodiazepines and CNS depressants; neonatal opioid withdrawal syndrome; risk of serotonin syndrome; severe hypotension; adrenal insufficiency; use in patients with head injury or increased intracranial pressure; seizures; avoid in patients with severe hepatic impairment.

Contraindications
ABILIFY MAINTENA KIT

Hypersensitivity to aripiprazole or any excipients in the formulation.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Hypersensitivity to any component; significant respiratory depression; acute or severe bronchial asthma; GI obstruction; suspected surgical abdomen; concomitant use with MAOIs or within 14 days; severe hepatic impairment.

Adverse Reactions
ABILIFY MAINTENA KIT
Data Pending
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Data Pending
Food Interactions
ABILIFY MAINTENA KIT

No specific food interactions. Grapefruit/grapefruit juice may increase aripiprazole levels (CYP3A4 inhibition). Avoid excessive alcohol consumption.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Avoid alcohol; may increase risk of hepatotoxicity and CNS depression. High-fat meals may delay absorption but do not significantly affect overall exposure. Caffeine-containing foods and beverages may increase stimulant effects.

Pregnancy & Lactation

ABILIFY MAINTENA KIT
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Teratogenic Risk
ABILIFY MAINTENA KIT

First trimester: Limited data, but aripiprazole is not a major human teratogen based on available studies. Second and third trimesters: Neonates exposed to antipsychotics, including aripiprazole, during the third trimester are at risk for extrapyramidal and/or withdrawal symptoms post-delivery.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: Generally considered low risk; no consistent evidence of teratogenicity. Caffeine: High doses (>200 mg/day) associated with increased miscarriage risk; limited data on malformations. Dihydrocodeine: Opioid; first trimester: increased risk of neural tube defects (OR 2.0-2.5); third trimester: risk of neonatal opioid withdrawal syndrome (NOWS). Overall, combination product should be used only if benefit outweighs risks.

Lactation Summary
ABILIFY MAINTENA KIT

Aripiprazole is excreted in human breast milk; the estimated infant dose is 0.7–1.4% of maternal weight-adjusted dose. M/P ratio: approximately 0.3–0.5. Limited data suggest no adverse effects in breastfed infants, but long-term safety is unknown.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Acetaminophen: Excreted in breast milk (M/P ratio ~0.9); safe at therapeutic doses. Caffeine: Excreted (M/P ~0.5-0.8); moderate intake (<300 mg/day) generally safe. Dihydrocodeine: Excreted in low levels; however, interindividual variability in metabolism (CYP2D6) may lead to higher morphine concentrations in some infants; risk of neonatal respiratory depression. M/P ratio not well established for dihydrocodeine. Use with caution, monitor infant for sedation and feeding difficulties.

Pregnancy Dosing
ABILIFY MAINTENA KIT

No specific dose adjustment recommended based on pharmacokinetic changes; however, therapeutic drug monitoring may be considered due to altered metabolism in pregnancy. The long-acting injectable formulation (Abilify Maintena) requires careful timing of doses postpartum to avoid relapse.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

No specific dose adjustments for pregnancy due to lack of pharmacokinetic studies for this combination. However, note: Increased clearance of acetaminophen in pregnancy may require higher doses for analgesia but remains within standard limits. Caffeine clearance decreases in third trimester; consider reducing intake to <200 mg/day. Dihydrocodeine: Increased volume of distribution and clearance in pregnancy; dose may need titration but no established guidelines. Use lowest effective dose for shortest duration.

Maternal Safety Status
ABILIFY MAINTENA KIT
Category C
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Category D/X

Clinical Insights

ABILIFY MAINTENA KIT
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE
Clinical Pearls
ABILIFY MAINTENA KIT

Administer every 4 weeks by intramuscular injection only. Do not substitute for oral aripiprazole on a mg-per-mg basis due to different pharmacokinetics. Requires initiation and continuation with oral aripiprazole for 14 days to establish tolerability. Monitor for neuroleptic malignant syndrome, tardive dyskinesia, and metabolic changes. Dose adjustments needed in patients with known CYP2D6 poor metabolizer status or concurrent use of strong CYP2D6 or CYP3A4 inhibitors.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Dihydrocodeine is a prodrug requiring CYP2D6 metabolism to active metabolites; poor metabolizers may have reduced efficacy while ultrarapid metabolizers risk toxicity. Caffeine potentiates analgesia and may cause insomnia with evening use. Do not exceed 8 tablets per 24 hours due to acetaminophen hepatotoxicity risk. Use with caution in elderly and patients with renal impairment.

Patient Counseling
ABILIFY MAINTENA KIT

This medication is given as an injection every 4 weeks by a healthcare professional.,Do not stop taking your oral aripiprazole until your doctor tells you to.,Seek emergency care if you experience fever, muscle stiffness, confusion, or irregular heartbeat.,Avoid alcohol and driving until you know how this medicine affects you.,Report any uncontrolled movements of the face, tongue, or other body parts to your doctor.,Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding.

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Take with food if stomach upset occurs.,Avoid alcohol and products containing acetaminophen to prevent liver damage.,Do not exceed 8 tablets in 24 hours.,May cause drowsiness; avoid driving or operating machinery until you know how this medication affects you.,If you have a history of drug dependence, use with caution as dihydrocodeine can be habit-forming.

Safety Verification

Known Interactions

ABILIFY MAINTENA KIT Risks

No interactions on record

ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE Risks3
Chlordiazepoxide + Dihydrocodeine
moderate

"The combination of chlordiazepoxide, a benzodiazepine that enhances GABAergic inhibition, and dihydrocodeine, an opioid agonist primarily at mu-receptors, results in additive central nervous system (CNS) depression. This synergy increases the risk of profound sedation, respiratory depression, coma, and death, particularly in vulnerable populations such as the elderly or those with pre-existing respiratory compromise. Concurrent use also elevates the potential for hypotension and psychomotor impairment, leading to falls or accidents."

Reserpine + Dihydrocodeine
moderate

"Reserpine depletes catecholamines in the central nervous system and peripheral adrenergic neurons, leading to reduced sympathetic outflow. Dihydrocodeine, an opioid agonist, can cause further central nervous system depression and hypotension. When combined, there is an additive risk of excessive hypotension, bradycardia, and profound sedation, potentially leading to falls or respiratory depression."

Dihydrocodeine + Clemastine
moderate

"Dihydrocodeine, an opioid analgesic, undergoes O-demethylation primarily via CYP2D6 to form dihydromorphine, which contributes to its analgesic effects. Clemastine, a first-generation antihistamine, is metabolized mainly by CYP2D6 as well. When co-administered, clemastine competitively inhibits CYP2D6, reducing the clearance of dihydrocodeine and decreasing the formation of the active metabolite dihydromorphine. This can lead to diminished analgesic efficacy and potentially increased levels of parent dihydrocodeine, heightening the risk of opioid-related adverse effects such as respiratory depression, sedation, and constipation."

Compare Alternatives

Related Drug Comparisons

Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.

ABILIFY MAINTENA KIT vs ABILIFYAtypical antipsychotic
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE vs ABILIFYAtypical antipsychotic
ABILIFY MAINTENA KIT vs ABILIFY ASIMTUFIIAtypical antipsychotic
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE vs ABILIFY ASIMTUFIIAtypical antipsychotic
ABILIFY MAINTENA KIT vs ABILIFY MYCITE KITAtypical antipsychotic
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE vs ABILIFY MYCITE KITAtypical antipsychotic
ABILIFY MAINTENA KIT vs ARIPIPRAZOLEAtypical Antipsychotic
ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE vs ARIPIPRAZOLEAtypical Antipsychotic
ABILIFY MAINTENA KIT vs ARISTADAAtypical Antipsychotic
Clinical Q&A

Frequently Asked Questions

Common clinical questions about ABILIFY MAINTENA KIT vs ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE, answered by our medical review team.

1. What is the main difference between ABILIFY MAINTENA KIT and ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE?

ABILIFY MAINTENA KIT is a Atypical antipsychotic that works by Aripiprazole is a partial agonist at D2 and 5-HT1A receptors and an antagonist at 5-HT2A receptors, stabilizing dopamine and serotonin activity.. ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE is a Opioid Agonist that works by Acetaminophen: inhibits cyclooxygenase (COX) activity, reducing prostaglandin synthesis; analgesic and antipyretic. Caffeine: adenosine receptor antagonist; enhances analgesic effect. Dihydrocodeine: mu-opioid receptor agonist; produces analgesia via central opioid receptors.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.

2. Which is stronger: ABILIFY MAINTENA KIT or ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE?

Potency comparisons between ABILIFY MAINTENA KIT and ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.

3. What is the standard dosing for ABILIFY MAINTENA KIT vs ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE?

The standard adult dose of ABILIFY MAINTENA KIT is: 400 mg IM once monthly after establishing tolerability with oral aripiprazole.. The standard adult dose of ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE is: 1-2 tablets (each containing acetaminophen 300 mg, caffeine 30 mg, dihydrocodeine bitartrate 20 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.

4. Can you take ABILIFY MAINTENA KIT and ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE together?

No direct drug-drug interaction has been formally documented between ABILIFY MAINTENA KIT and ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.

5. Are ABILIFY MAINTENA KIT and ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE safe during pregnancy?

The maternal-fetal safety profiles differ. ABILIFY MAINTENA KIT is classified as Category C. First trimester: Limited data, but aripiprazole is not a major human teratogen based on available studies. Second and third trimesters: Neonates exposed to antipsychotics, includin. ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE is classified as Category D/X. Acetaminophen: Generally considered low risk; no consistent evidence of teratogenicity. Caffeine: High doses (>200 mg/day) associated with increased miscarriage risk; limited data . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.