Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ALFENTA 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
μ-opioid receptor agonist that activates G-protein coupled receptors to inhibit adenylate cyclase, decreasing c AMP production, leading to reduced neuronal excitability and pain transmission.
Androgen receptor agonist; stimulates protein synthesis and growth of androgen-sensitive tissues.
Induction and maintenance of anesthesia,Analgesic supplement during surgical procedures,Intravenous use for monitored anesthesia care (MAC)
Testosterone replacement therapy for male hypogonadism,Off-label: delayed puberty in males
Intravenous: Initial dose 8-20 mcg/kg (0.5-1 min) then 0.5-3 mcg/kg/min or 3-5 mcg/kg q5-20min. For short procedures: 8-20 mcg/kg. For longer procedures: 50-75 mcg/kg followed by 0.5-3 mcg/kg/min.
2.5-10 mg orally once daily in the morning for androgen replacement therapy in adult males.
Terminal elimination half-life: 90–111 minutes (1.5–1.85 hours); prolonged in hepatic impairment.
Terminal elimination half-life is 3.5–5.5 hours; clinical effects may persist for several days due to active metabolites.
Hepatic via CYP3A4 to inactive metabolites; major metabolite is desmethylalfentanil (inactive).
Hepatic via CYP3A4 and CYP2B6; undergoes first-pass metabolism.
Primarily renal (urinary) elimination as metabolites; approximately 80% recovered in urine, 20% in feces.
Primarily renal: ~90% as glucuronide and sulfate conjugates, 6% as unchanged drug; ~5% fecal via bile.
Approximately 92% bound, primarily to alpha-1 acid glycoprotein and albumin.
98% bound to sex hormone-binding globulin (SHBG) and albumin.
0.5–1.0 L/kg; reflects moderate tissue distribution; higher Vd in neonates and elderly.
Vd approximately 1.0 L/kg; indicates extensive tissue distribution, especially to reproductive organs and bone marrow.
Intravenous: 100%; intramuscular: approximately 90%; intrathecal: approximately 10% (due to systemic absorption following spinal administration).
Oral: 15–25% due to first-pass metabolism; buccal or transdermal: higher, but not commercially available for this formulation.
No specific dose adjustment is recommended for renal impairment; however, alfentanil is primarily metabolized in the liver and its pharmacokinetics are not significantly altered in renal failure.
No specific dose adjustment required based on GFR; caution in severe impairment (Cr Cl <30 m L/min) due to potential fluid retention.
In hepatic impairment (Child-Pugh class A, B, C): Reduce dose by 50% and titrate carefully due to prolonged elimination half-life. Consider lower initial doses and extended dosing intervals.
Contraindicated in Child-Pugh class B and C cirrhosis due to hepatotoxicity risk; in class A, use with caution and monitor liver function.
Children (1-12 years): Induction of anesthesia: 10-20 mcg/kg IV; maintenance: 5-10 mcg/kg IV or infusion 0.5-1 mcg/kg/min. For neonates and infants: Dose individualization required; titrate to effect.
Not recommended for use in children as it may cause premature epiphyseal closure and virilization; limited data.
Elderly patients (>65 years): Reduce initial dose by 30-50% and administer slowly. Due to decreased clearance and increased sensitivity, lower infusion rates (e.g., 0.3-0.5 mcg/kg/min) may be needed.
Increased risk of prostatic hyperplasia and carcinoma; use lowest effective dose with regular prostate monitoring.
Risk of respiratory depression, particularly in elderly or debilitated patients. Concomitant use with benzodiazepines or other CNS depressants may cause profound sedation, respiratory depression, coma, and death.
Warning: Prolonged use may cause virilization in women, premature epiphyseal closure, and increased risk of prostatic hypertrophy/carcinoma.
Respiratory depression; abuse potential; hypotension; bradycardia; muscle rigidity; serotonin syndrome with concurrent serotonergic drugs; adrenal insufficiency; risk of withdrawal with prolonged use.
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 alfentanil or any component; significant respiratory insufficiency; severe asthma; paralytic ileus; concurrent use of MAOIs (or within 14 days); acute or postoperative pain management in children (except for procedural sedation).
Known or suspected prostate cancer; breast cancer in males; hypersensitivity to androgens; pregnancy and lactation.
No known interactions with food. However, grapefruit juice may increase alfentanil serum concentrations due to CYP3A4 inhibition; avoid concurrent consumption.
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.
Alfentanil, a short-acting opioid analgesic, is classified as FDA Pregnancy Category C. No well-controlled studies in pregnant women exist. In animal studies, no teratogenic effects were observed at clinically relevant doses; however, high doses caused embryotoxicity and increased fetal mortality. Trimester-specific risks: First trimester - potential for minor malformations based on limited human data; second trimester - possible risk if used chronically; third trimester - prolonged use may lead to neonatal respiratory depression, withdrawal syndrome, or opioid dependence. Use only if benefits outweigh risks.
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.
Alfentanil is excreted into human breast milk in low concentrations. The milk-to-plasma (M/P) ratio is approximately 0.3. Estimated infant dose is <1% of maternal weight-adjusted dose, which is considered clinically insignificant. However, due to potential for neonatal opioid effects, caution is advised; monitor infant for drowsiness, respiratory depression, and feeding difficulties. Consider alternative analgesics with established safety profiles, such as acetaminophen or ibuprofen, for lactation.
Excretion into human milk is unknown. Due to potential for androgenic effects in nursing infants, breastfeeding is not recommended. No M/P ratio available.
Pregnancy can alter pharmacokinetics of alfentanil. Increased plasma volume and distribution may require higher doses to achieve same effect, while decreased plasma protein binding may increase free fraction, potentiating effects. Alpha-1-acid glycoprotein levels change in pregnancy, affecting binding. In third trimester, clearance may be increased by up to 50% due to enhanced hepatic metabolism. Therefore, dose adjustments may be needed: consider starting at low dose and titrating to effect, with close monitoring. For intravenous administration, typical adult doses (5-20 μg/kg) may need adjustments; no standard pregnancy-specific dosing exists. Use the lowest effective dose for the shortest duration. In labor, avoid high doses prior to delivery due to risk of neonatal respiratory depression.
Not applicable; contraindicated in pregnancy. No dose adjustment recommendations exist for pregnant patients.
Alfentanil is a potent, rapid-onset, short-acting opioid analgesic used primarily for induction and maintenance of anesthesia. Due to its high protein binding (90%) and rapid redistribution, it has a shorter duration of action than fentanyl, making it suitable for brief, painful procedures. It undergoes hepatic metabolism via CYP3A4, so concomitant use with CYP3A4 inhibitors like ketoconazole or erythromycin can prolong its effects. Use caution in elderly or hypovolemic patients due to increased risk of hypotension. Naloxone reverses respiratory depression. Alfentanil is 5-10 times less potent than fentanyl.
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.
This medication is given only by a healthcare professional in a hospital or surgical setting.,You may feel drowsy, dizzy, or nauseated after receiving this drug.,Report any difficulty breathing or slow heart rate to your healthcare provider immediately.,Avoid alcohol and sedatives for 24 hours after administration, as they can increase side effects.,Do not drive or operate machinery until the effects have fully worn off.
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.
"Propantheline, an anticholinergic agent, can competitively antagonize muscarinic acetylcholine receptors, potentially reducing gastrointestinal motility and secretion. Alfentanil, a mu-opioid receptor agonist, also decreases gastrointestinal motility through central and peripheral opioid receptors. Concomitant use may synergistically inhibit peristalsis, leading to severe constipation, paralytic ileus, or delayed gastric emptying, which can increase the risk of aspiration and complicate anesthesia recovery."
"Alfentanil, a potent opioid analgesic, can cause significant hypotension and respiratory depression. When combined with furosemide, a loop diuretic that reduces blood volume and vascular resistance, there is a synergistic decrease in blood pressure, which may precipitate cardiovascular collapse, especially in patients with compromised circulatory reserves. Additionally, furosemide may enhance the sedative and respiratory depressant effects of alfentanil, leading to increased risk of respiratory acidosis and altered mental status."
"Alfentanil, a potent mu-opioid receptor agonist, can enhance the bradycardic effects of nebivolol, a beta-1 selective blocker with additional nitric oxide-mediated vasodilation. The combination may lead to excessive slowing of heart rate, reduced cardiac output, and potential hemodynamic instability, particularly in patients with underlying cardiac conduction abnormalities or hypovolemia."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ALFENTA vs ANDROID 5, answered by our medical review team.
ALFENTA is a Opioid Analgesic that works by μ-opioid receptor agonist that activates G-protein coupled receptors to inhibit adenylate cyclase, decreasing c AMP production, leading to reduced neuronal excitability and pain transmission.. 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 ALFENTA 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 ALFENTA is: Intravenous: Initial dose 8-20 mcg/kg (0.5-1 min) then 0.5-3 mcg/kg/min or 3-5 mcg/kg q5-20min. For short procedures: 8-20 mcg/kg. For longer procedures: 50-75 mcg/kg followed by 0.5-3 mcg/kg/min.. 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 ALFENTA 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. ALFENTA is classified as Category C. Alfentanil, a short-acting opioid analgesic, is classified as FDA Pregnancy Category C. No well-controlled studies in pregnant women exist. In animal studies, no teratogenic effect. 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.