Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CLOMID vs ACETAMINOPHEN AND CODEINE PHOSPHATE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Competitive antagonist of estrogen receptors (ER) in hypothalamus and pituitary, leading to increased gonadotropin-releasing hormone (Gn RH) and subsequent LH and FSH release, stimulating ovulation.
Acetaminophen: centrally acting analgesic and antipyretic, possibly via inhibition of cyclooxygenase (COX) and modulation of cannabinoid receptors. Codeine: prodrug converted to morphine; mu-opioid receptor agonist.
Treatment of ovulatory dysfunction in women desiring pregnancy (FDA approved),Off-label: treatment of male infertility (oligospermia)
Mild to moderate pain,Pain accompanied by fever
50 mg orally once daily for 5 days, starting on day 5 of the menstrual cycle. May increase to 100 mg daily if no response.
One or two tablets (acetaminophen 300 mg/codeine 30 mg per tablet) orally every 4-6 hours as needed for pain; maximum 12 tablets daily.
Terminal half-life is 5–7 days for zuclomiphene (active isomer), with prolonged elimination due to enterohepatic recirculation.
Acetaminophen: 2–3 hours (prolonged in hepatic impairment). Codeine: 2.5–3.5 hours; metabolites: morphine 1.5–2.5 hours, codeine-6-glucuronide 3–4 hours. Clinical context: dosing interval every 4–6 hours.
Hepatic via CYP3A4 and CYP2D6; undergoes enterohepatic circulation; terminal half-life ~5-7 days
Acetaminophen: primarily glucuronidation and sulfation in liver; minor CYP450 (CYP2E1) to toxic NAPQI. Codeine: CYP2D6 to morphine; CYP3A4 to norcodeine; glucuronidation.
Primarily hepatic metabolism; metabolites excreted in feces (42%) and urine (8% unchanged).
Acetaminophen: renal elimination of conjugated metabolites (glucuronide 60%, sulfate 30%, cysteine/mercapturate <5%), less than 5% unchanged. Codeine: renal elimination of codeine (5–15%), morphine (5–10%), norcodeine (10–20%), and conjugates; 90% excreted in urine within 24 hours.
Highly protein bound (>99%), primarily to albumin.
Acetaminophen: 10–25% (albumin). Codeine: 7–25% (primarily albumin).
Not well-characterized; limited data suggest a large Vd (>100 L) due to extensive tissue distribution.
Acetaminophen: 0.9 L/kg. Codeine: 3–6 L/kg (extensive tissue distribution).
Oral bioavailability is approximately 50% due to first-pass metabolism.
Oral: acetaminophen 88% (variable first-pass); codeine 50–60% (first-pass metabolism to morphine, norcodeine, and conjugates).
No specific adjustment required; use caution in severe impairment (Cr Cl <30 m L/min) as data limited.
GFR 30-50 m L/min: administer every 6 hours; GFR 10-29 m L/min: administer every 8 hours; GFR <10 m L/min: administer every 12 hours; hemodialysis: not recommended.
Contraindicated in severe hepatic impairment (Child-Pugh class C). For mild to moderate impairment, no adjustment recommended, but monitor liver function.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% and extend interval to every 8 hours; Child-Pugh C: contraindicated.
Not indicated for use in children; safety and efficacy not established.
For children ≥12 years: acetaminophen 10-15 mg/kg/dose and codeine 0.5-1 mg/kg/dose orally every 4-6 hours; maximum acetaminophen 75 mg/kg/day, codeine 6 mg/kg/day. For children <12 years: not recommended due to codeine safety concerns.
Not indicated for postmenopausal women. Use not recommended in elderly due to lack of efficacy in anovulation.
Start with lowest effective dose; acetaminophen component maximum 3 g/day; consider reduced codeine dose (e.g., 15 mg) due to increased sensitivity and risk of respiratory depression; extend dosing interval to every 6-8 hours.
None
Risk of medication errors: confusion between milligram and milliliter doses, and between codeine and acetaminophen components. Contraindicated for postoperative pain management in children following tonsillectomy/adenoidectomy due to risk of respiratory depression and death.
Ovarian hyperstimulation syndrome (OHSS),Ovarian enlargement,Visual disturbances (especially with prolonged use),Multiple pregnancy (increased risk),Ectopic pregnancy,Ovarian cancer risk (theoretical, based on prolonged use)
Hepatotoxicity (acetaminophen overdose); respiratory depression; drug dependence; ultra-rapid metabolizers of codeine (CYP2D6) leading to morphine toxicity; concomitant CNS depressants; use in pediatric patients; avoid alcohol.
Pregnancy (Category X),Liver disease or dysfunction,Undiagnosed abnormal vaginal bleeding,Ovarian cyst or enlargement not due to polycystic ovary syndrome,Hypersensitivity to clomiphene or components
Hypersensitivity to acetaminophen or codeine; severe respiratory depression; acute or severe asthma; paralytic ileus; post-operative pain management in children after tonsillectomy/adenoidectomy; breastfeeding (in ultra-rapid metabolizers); concomitant MAOIs.
No specific food interactions. Avoid grapefruit as it may alter metabolism (theoretical due to CYP3A4 involvement).
Avoid alcohol; high-fat meals may delay absorption but not clinically significant.
Clomiphene citrate is contraindicated in pregnancy. It is associated with an increased risk of fetal malformations, including neural tube defects, specifically when exposure occurs during the first trimester. Second and third trimester risks are not well studied due to contraindication, but theoretical risks include ovarian hyperstimulation syndrome (OHSS) effects on pregnancy.
Acetaminophen is considered low risk in all trimesters at therapeutic doses; chronic high doses may be associated with adverse outcomes. Codeine is associated with risk of respiratory depression and neonatal withdrawal if used near term; may cause neural tube defects and other malformations with first-trimester exposure, but data are conflicting. Use lowest effective dose for shortest duration.
Safety in breastfeeding is not established. Clomiphene may reduce milk production. The M/P ratio is unknown. It is generally not recommended during breastfeeding.
Acetaminophen is excreted into breast milk in low amounts (M/P ratio ~0.91-1.42) and is considered compatible with breastfeeding. Codeine is also excreted in breast milk; risk of infant opioid toxicity depends on maternal CYP2D6 phenotype. Ultra-rapid metabolizers may produce higher morphine levels. Use with caution, avoid in known CYP2D6 ultra-rapid metabolizers, and monitor infant for sedation and respiratory depression.
No dose adjustments are relevant as clomiphene is contraindicated in pregnancy. Pharmacokinetic changes in pregnancy are not applicable due to contraindication.
No routine dose adjustment needed for acetaminophen. Codeine pharmacokinetics are altered in pregnancy: increased clearance and volume of distribution may require dose adjustment; however, due to variability in CYP2D6 metabolism, individualize dosing and monitor for efficacy and toxicity. Avoid codeine in pregnancy unless alternative analgesics are ineffective.
Monitor ovarian size via ultrasound to reduce risk of ovarian hyperstimulation syndrome (OHSS). Limit course to 3-6 cycles due to increased risk of ovarian tumors. Check pregnancy test before each cycle. Use with caution in liver disease.
For acute pain, limit codeine to 3 days; avoid in children under 12 due to CYP2D6 ultra-rapid metabolizer risk of fatal respiratory depression; monitor for constipation; assess liver function for acetaminophen hepatotoxicity; use with caution in renal impairment.
Take exactly as prescribed, typically 50 mg daily for 5 days starting on day 5 of menstrual cycle.,Report abdominal pain, bloating, nausea, or weight gain (possible OHSS).,Avoid alcohol due to hepatotoxicity risk.,Most pregnancies occur within first 3 cycles; consider alternative after 6 cycles.,May cause visual disturbances; report blurred vision or spots.
Take exactly as prescribed; do not exceed 4000 mg acetaminophen per day.,Avoid alcohol while taking this medication.,Do not use with other acetaminophen-containing products.,May cause dizziness or drowsiness; avoid driving until you know how you react.,Common side effects include constipation, nausea, and drowsiness.,Seek emergency if signs of allergic reaction or difficulty breathing occur.
No interactions on record
"Pirenzepine, a selective M1 muscarinic antagonist, reduces gastrointestinal motility and secretions, while codeine, an opioid agonist, also decreases gastrointestinal motility via mu-opioid receptors. Concurrent use leads to additive anticholinergic and opioid effects, resulting in enhanced risk of severe constipation, paralytic ileus, and central nervous system depression. Clinically, patients may experience exacerbated sedation, respiratory depression, and urinary retention."
"Ropinirole, a non-ergoline dopamine agonist used in Parkinson's disease and restless legs syndrome, may reduce the analgesic efficacy of codeine. This is likely due to pharmacodynamic antagonism at central dopamine and opioid receptors, as well as potential pharmacokinetic interactions that decrease the conversion of codeine to its active metabolite morphine via CYP2D6 inhibition by ropinirole. The resultant blunted opioid response can lead to inadequate pain control, necessitating dose adjustment or alternative therapy."
"Vemurafenib induces CYP3A4, significantly reducing the plasma concentrations of codeine, which is metabolized via CYP3A4 to its active metabolite morphine. This may diminish codeine's analgesic efficacy, potentially leading to inadequate pain control. Additionally, reduced formation of morphine may lower the risk of opioid-related adverse effects."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about CLOMID vs ACETAMINOPHEN AND CODEINE PHOSPHATE, answered by our medical review team.
CLOMID is a Selective Estrogen Receptor Modulator that works by Competitive antagonist of estrogen receptors (ER) in hypothalamus and pituitary, leading to increased gonadotropin-releasing hormone (Gn RH) and subsequent LH and FSH release, stimulating ovulation.. ACETAMINOPHEN AND CODEINE PHOSPHATE is a Opioid Agonist that works by Acetaminophen: centrally acting analgesic and antipyretic, possibly via inhibition of cyclooxygenase (COX) and modulation of cannabinoid receptors. Codeine: prodrug converted to morphine; mu-opioid receptor agonist.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CLOMID and ACETAMINOPHEN AND CODEINE PHOSPHATE 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 CLOMID is: 50 mg orally once daily for 5 days, starting on day 5 of the menstrual cycle. May increase to 100 mg daily if no response.. The standard adult dose of ACETAMINOPHEN AND CODEINE PHOSPHATE is: One or two tablets (acetaminophen 300 mg/codeine 30 mg per tablet) orally every 4-6 hours as needed for pain; maximum 12 tablets daily.. 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 CLOMID and ACETAMINOPHEN AND CODEINE PHOSPHATE 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. CLOMID is classified as Category C. Clomiphene citrate is contraindicated in pregnancy. It is associated with an increased risk of fetal malformations, including neural tube defects, specifically when exposure occurs. ACETAMINOPHEN AND CODEINE PHOSPHATE is classified as Category D/X. Acetaminophen is considered low risk in all trimesters at therapeutic doses; chronic high doses may be associated with adverse outcomes. Codeine is associated with risk of respirat. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.