Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE vs ANDROID 5
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Pentazocine is a mixed agonist-antagonist opioid analgesic that binds to mu, kappa, and sigma opioid receptors, primarily acting as an agonist at kappa receptors and partial agonist at mu receptors, resulting in analgesic and sedative effects. Acetaminophen (paracetamol) is an analgesic and antipyretic whose mechanism involves inhibition of cyclooxygenase (COX) enzymes, primarily COX-2, in the central nervous system, and possibly activation of descending serotonergic pathways.
Androgen receptor agonist; stimulates protein synthesis and growth of androgen-sensitive tissues.
Moderate to severe pain where an opioid analgesic is appropriate
Testosterone replacement therapy for male hypogonadism,Off-label: delayed puberty in males
One tablet (acetaminophen 500 mg / pentazocine hydrochloride 25 mg) orally every 4 hours as needed for pain; maximum daily dose: acetaminophen 4000 mg (8 tablets) and pentazocine hydrochloride 200 mg (8 tablets).
2.5-10 mg orally once daily in the morning for androgen replacement therapy in adult males.
Acetaminophen: 2-3 hours (prolonged in hepatic impairment). Pentazocine: 2-3 hours (terminal), with clinical analgesic effect lasting 3-4 hours.
Terminal elimination half-life is 3.5–5.5 hours; clinical effects may persist for several days due to active metabolites.
Pentazocine is extensively metabolized in the liver via oxidation and glucuronidation; significant first-pass metabolism. Acetaminophen is metabolized primarily in the liver via conjugation with glucuronide and sulfate, and oxidation via CYP2E1, CYP1A2, and CYP3A4 to a toxic metabolite (NAPQI).
Hepatic via CYP3A4 and CYP2B6; undergoes first-pass metabolism.
Acetaminophen: renal (2-4% unchanged, ~85% as glucuronide and sulfate conjugates). Pentazocine: renal (~60% as unchanged and conjugates), biliary/fecal (~20%).
Primarily renal: ~90% as glucuronide and sulfate conjugates, 6% as unchanged drug; ~5% fecal via bile.
Acetaminophen: 10-25% (albumin). Pentazocine: 60-70% (albumin and alpha-1 acid glycoprotein).
98% bound to sex hormone-binding globulin (SHBG) and albumin.
Acetaminophen: 0.9 L/kg. Pentazocine: 5-7 L/kg (extensive tissue distribution).
Vd approximately 1.0 L/kg; indicates extensive tissue distribution, especially to reproductive organs and bone marrow.
Acetaminophen oral: 60-90%. Pentazocine oral: ~20% (extensive first-pass metabolism). Intramuscular: pentazocine 100%.
Oral: 15–25% due to first-pass metabolism; buccal or transdermal: higher, but not commercially available for this formulation.
Cr Cl 30-50 m L/min: use with caution; decrease dose interval to every 6 hours if needed. Cr Cl <30 m L/min: restrict pentazocine; consider alternative. Not recommended for patients on dialysis.
No specific dose adjustment required based on GFR; caution in severe impairment (Cr Cl <30 m L/min) due to potential fluid retention.
Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce pentazocine dose by 50%; avoid acetaminophen >2 g/day. Child-Pugh Class C: contraindicated due to acetaminophen hepatotoxicity and pentazocine accumulation.
Contraindicated in Child-Pugh class B and C cirrhosis due to hepatotoxicity risk; in class A, use with caution and monitor liver function.
Not recommended in children <12 years due to lack of safety data. For adolescents ≥12 years, adult dosing may be considered based on weight (≥50 kg).
Not recommended for use in children as it may cause premature epiphyseal closure and virilization; limited data.
Reduce pentazocine dose by 50% (e.g., one tablet every 6 hours) due to increased risk of CNS depression, confusion, and constipation. Monitor renal function; avoid exceeding 4 g/day acetaminophen.
Increased risk of prostatic hyperplasia and carcinoma; use lowest effective dose with regular prostate monitoring.
Pentazocine: Risk of respiratory depression, particularly in elderly, cachectic, or debilitated patients. Concomitant use with benzodiazepines or other CNS depressants may result in profound sedation, respiratory depression, coma, and death. Patients should be monitored for respiratory depression and sedation.
Warning: Prolonged use may cause virilization in women, premature epiphyseal closure, and increased risk of prostatic hypertrophy/carcinoma.
Respiratory depression risk, especially in patients with compromised respiratory function,Potential for opioid dependence, abuse, and misuse,Risk of withdrawal if discontinued abruptly after prolonged use,Pentazocine may cause opioid withdrawal in patients dependent on pure mu agonists,Acetaminophen hepatotoxicity at high doses or with chronic use; risk increased with alcohol consumption or pre-existing liver disease,Central nervous system depression additive with other CNS depressants,Elderly or debilitated patients may have increased sensitivity to effects,May cause hypotension, especially in hypovolemic patients,Serotonin syndrome risk when used with serotonergic drugs,Pentazocine may cause hallucinations, confusion, or other psychotomimetic effects
Monitor liver function, lipid profile, and prostate-specific antigen; risk of edema in patients with cardiac disease; avoid use in patients with sleep apnea.
Hypersensitivity to either component,Severe respiratory depression (e.g., acute asthma, hypercapnia),Acute or severe bronchial asthma,Suspected surgical abdomen (may obscure diagnosis),Monoamine oxidase inhibitor (MAOI) use (current or within 14 days),Severe hepatic impairment or active liver disease (acetaminophen component),Known or suspected gastrointestinal obstruction (including paralytic ileus)
Known or suspected prostate cancer; breast cancer in males; hypersensitivity to androgens; pregnancy and lactation.
Avoid alcohol consumption due to increased risk of hepatotoxicity from acetaminophen. No specific food interactions; take with food if gastrointestinal upset occurs.
Avoid grapefruit and grapefruit juice as they may increase drug levels. Limit salt intake to reduce fluid retention. Alcohol may increase risk of liver toxicity.
Acetaminophen: Generally considered low risk; no consistent evidence of teratogenicity in any trimester. Pentazocine: Limited human data; animal studies show no teratogenicity at clinically relevant doses. However, use in third trimester may cause neonatal respiratory depression and withdrawal syndrome. Overall, risk is low but pentazocine should be avoided near term.
Pregnancy Category X. ANDROID 5 (oxandrolone) is contraindicated in pregnancy due to teratogenic effects including masculinization of female fetus, clitoral enlargement, and labial fusion. Risk is highest during first trimester but applies throughout gestation.
Acetaminophen: Excreted in low amounts (M/P ratio ~0.2-0.9); compatible with breastfeeding. Pentazocine: Excreted in breast milk; M/P ratio unknown; may cause CNS effects in infants. Use with caution, especially in neonates or premature infants. Monitor infant for sedation and respiratory depression.
Excretion into human milk is unknown. Due to potential for androgenic effects in nursing infants, breastfeeding is not recommended. No M/P ratio available.
Acetaminophen: No significant pharmacokinetic changes in pregnancy; standard dosing (max 3-4 g/day) applies. Pentazocine: Clearance may increase due to enhanced hepatic metabolism; dose adjustments not routinely recommended but monitor response. Avoid high doses near term due to risk of neonatal depression.
Not applicable; contraindicated in pregnancy. No dose adjustment recommendations exist for pregnant patients.
Pentazocine is a mixed agonist-antagonist opioid; avoid in opioid-dependent patients due to risk of precipitated withdrawal. Acetaminophen component limits total daily dose to 4 g (or less in hepatic impairment) to prevent hepatotoxicity. Monitor for respiratory depression, especially in elderly or those with COPD. Injection site reactions (e.g., sterile abscesses, fibrosis) common with repeated intramuscular use. May cause dysphoria, hallucinations, or CNS stimulation (unlike typical opioids). Contraindicated in acute porphyria due to porphyrinogenic potential.
Android 5 (methyltestosterone) is an androgenic anabolic steroid used for hypogonadism and delayed puberty. Monitor liver function due to hepatotoxicity. Use with caution in elderly due to increased risk of prostatic hypertrophy and carcinoma. Can cause fluid retention in patients with cardiac, renal, or hepatic disease. Avoid in patients with breast cancer or known or suspected prostate cancer.
Do not exceed 4 grams of acetaminophen per day from all sources (including OTC medications).,Avoid alcohol while taking this medication; risk of liver damage increases.,This medication may cause dizziness, drowsiness, or hallucinations; avoid driving or operating machinery until effects are known.,Report any signs of allergic reaction (rash, difficulty breathing) or liver issues (yellow skin/eyes, dark urine).,Do not suddenly stop if used long-term; withdrawal symptoms may occur.,If you have opioid dependence, this medication may precipitate withdrawal symptoms.,This medication may cause constipation; maintain fluid and fiber intake.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Report any signs of liver problems: yellowing of skin or eyes, dark urine, severe stomach pain.,Women should report any signs of virilization: hoarseness, acne, menstrual changes, growth of facial hair.,Men should report any breast enlargement, changes in urination, or priapism.,Avoid driving or operating machinery if you experience dizziness or drowsiness.,Do not use if you are pregnant or planning to become pregnant.
"Pentazocine, a mixed opioid agonist-antagonist, may attenuate the central nervous system (CNS) stimulant effects of dextroamphetamine by competitively blocking mu-opioid receptors and potentially altering dopamine release, leading to reduced analgesic efficacy of pentazocine and diminished therapeutic response to dextroamphetamine in treating attention deficit hyperactivity disorder (ADHD) or narcolepsy. This interaction can result in suboptimal pain control and exacerbation of ADHD symptoms, requiring dose adjustments or alternative therapies."
"The concurrent use of ipratropium, an anticholinergic agent, and pentazocine, a mixed opioid agonist-antagonist, may lead to an increased risk of central nervous system (CNS) depression and anticholinergic adverse effects. Pentazocine can enhance the sedative and respiratory depressant effects of ipratropium, while ipratropium may potentiate pentazocine's anticholinergic actions, such as dry mouth, blurred vision, constipation, and urinary retention. Clinically, this interaction can result in excessive sedation, confusion, and impaired cognitive and motor function, particularly in elderly or debilitated patients."
"The combination of pentazocine, a mixed agonist-antagonist opioid, with triazolam, a benzodiazepine, can lead to additive central nervous system (CNS) depression, including increased sedation, respiratory depression, and psychomotor impairment. This is due to the synergistic effects of both drugs on GABAergic and opioid receptors in the brainstem and cortex. Clinically, this may result in excessive drowsiness, confusion, ataxia, and an elevated risk of falls or respiratory compromise, particularly in elderly or debilitated patients."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE vs ANDROID 5, answered by our medical review team.
ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE is a Opioid Agonist-Antagonist that works by Pentazocine is a mixed agonist-antagonist opioid analgesic that binds to mu, kappa, and sigma opioid receptors, primarily acting as an agonist at kappa receptors and partial agonist at mu receptors, resulting in analgesic and sedative effects. Acetaminophen (paracetamol) is an analgesic and antipyretic whose mechanism involves inhibition of cyclooxygenase (COX) enzymes, primarily COX-2, in the central nervous system, and possibly activation of descending serotonergic pathways.. ANDROID 5 is a Androgen that works by Androgen receptor agonist; stimulates protein synthesis and growth of androgen-sensitive tissues.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE and ANDROID 5 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.
The standard adult dose of ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE is: One tablet (acetaminophen 500 mg / pentazocine hydrochloride 25 mg) orally every 4 hours as needed for pain; maximum daily dose: acetaminophen 4000 mg (8 tablets) and pentazocine hydrochloride 200 mg (8 tablets).. The standard adult dose of ANDROID 5 is: 2.5-10 mg orally once daily in the morning for androgen replacement therapy in adult males.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE and ANDROID 5 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.
The maternal-fetal safety profiles differ. ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE is classified as Category A/B. Acetaminophen: Generally considered low risk; no consistent evidence of teratogenicity in any trimester. Pentazocine: Limited human data; animal studies show no teratogenicity at c. ANDROID 5 is classified as Category C. Pregnancy Category X. ANDROID 5 (oxandrolone) is contraindicated in pregnancy due to teratogenic effects including masculinization of female fetus, clitoral enlargement, and labial. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.