Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
GONITRO 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
Nitric oxide (NO) donor; activates guanylyl cyclase, increasing c GMP in vascular smooth muscle, leading to vasodilation.
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.
Prevention of angina pectoris due to coronary artery disease,Acute relief of angina episodes,Prophylaxis for angina before exertion or stress
Mild to moderate pain,Pain accompanied by fever
Sublingual: 0.3-0.6 mg at onset of angina, may repeat every 5 minutes up to 3 doses within 15 minutes. Prophylactic: 0.3-0.6 mg 5-10 minutes before activity. Transdermal: Apply 0.2-0.8 mg/hour patch once daily, remove at bedtime to prevent tolerance. Intravenous: Start at 5 mcg/min, titrate by 5-20 mcg/min every 3-5 minutes based on hemodynamic response; usual range 10-200 mcg/min.
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 elimination half-life approximately 2-3 minutes for nitroglycerin; clinical effects cease within 30-60 minutes due to rapid redistribution and metabolism
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.
Extensively metabolized by mitochondrial aldehyde dehydrogenase (ALDH2) in vascular smooth muscle; also metabolized by glutathione S-transferases and cytochrome P450 (CYP3A4).
Acetaminophen: primarily glucuronidation and sulfation in liver; minor CYP450 (CYP2E1) to toxic NAPQI. Codeine: CYP2D6 to morphine; CYP3A4 to norcodeine; glucuronidation.
Primarily renal: 80-90% as inactive metabolites (dinitrates, mononitrates); minor biliary/fecal (<10%)
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.
60% bound, primarily to plasma albumin
Acetaminophen: 10–25% (albumin). Codeine: 7–25% (primarily albumin).
Approximately 3.3 L/kg; extensive tissue distribution with high affinity for vascular smooth muscle
Acetaminophen: 0.9 L/kg. Codeine: 3–6 L/kg (extensive tissue distribution).
Sublingual: 40-60%; Oral (immediate-release): <10% due to first-pass hepatic metabolism; Transdermal: 70-90% (drug-in-adhesive); Intravenous: 100%
Oral: acetaminophen 88% (variable first-pass); codeine 50–60% (first-pass metabolism to morphine, norcodeine, and conjugates).
No specific dose adjustment required for renal impairment. However, use with caution in severe renal dysfunction (Cr Cl <30 m L/min) due to increased risk of hypotension and methemoglobinemia.
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.
Child-Pugh A: No adjustment needed. Child-Pugh B: Reduce dose by 50% due to decreased clearance. Child-Pugh C: Avoid use or use with extreme caution; consider alternative therapy.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% and extend interval to every 8 hours; Child-Pugh C: contraindicated.
Sublingual: 5-10 mcg/kg/dose, maximum 0.3 mg per dose, may repeat every 5 minutes up to 3 doses. Intravenous: Start at 0.25-0.5 mcg/kg/min, titrate up to 1-5 mcg/kg/min based on response. Not recommended for children <1 year due to limited data.
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.
Initiate at lower doses due to increased sensitivity: Sublingual: 0.15-0.3 mg; Transdermal: 0.2 mg/day patch; Intravenous: Start at 5 mcg/min, titrate slowly. Monitor for hypotension and syncope. Avoid sustained-release formulations due to prolonged half-life.
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.
Do not use with phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil) due to risk of severe hypotension.
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.
Hypotension (especially with volume depletion or diuretic therapy), reflex tachycardia, tolerance (intermittent dosing with nitrate-free interval recommended), abrupt discontinuation may cause angina rebound.
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.
Concomitant use with PDE-5 inhibitors (sildenafil, tadalafil, vardenafil), severe anemia, increased intracranial pressure, hypersensitivity to nitrates, acute myocardial infarction with low filling pressure.
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.
Avoid alcohol consumption as it may exacerbate nitroglycerin-induced hypotension and vasodilation. No specific food interactions documented; however, patients should maintain adequate hydration. High-fat meals may delay absorption, but sublingual route minimizes this effect. Grapefruit juice has no known interaction.
Avoid alcohol; high-fat meals may delay absorption but not clinically significant.
FDA Pregnancy Category C. First trimester: no increased risk of major malformations in human studies; animal studies show fetal toxicity at high doses. Second/third trimesters: risk of fetal bradycardia, hypotension, and reduced uteroplacental perfusion; avoid near term due to risk of maternal hypotension and neonatal bradycardia.
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.
Not recommended during breastfeeding. No data on M/P ratio; minimal excretion into breast milk expected but safety not established. Potential for infant hypotension and bradycardia.
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 standard dose adjustment required for pregnancy; use lowest effective dose. Increased plasma volume may reduce response; titrate to effect. Avoid in severe preeclampsia or volume depletion.
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.
GONITRO (nitroglycerin sublingual powder) is indicated for acute relief of angina pectoris. Administer one packet (0.4 mg or 0.8 mg) at onset of chest pain; may repeat every 5 minutes up to 3 doses. Ensure patient is seated or lying down to avoid hypotension. Do not confuse with oral spray; powder must be placed under tongue. Onset within 1-3 minutes. Common side effect: headache. Contraindicated with phosphodiesterase-5 inhibitors (e.g., sildenafil) within 24-48 hours due to severe hypotension. Monitor for orthostatic hypotension.
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 one packet at the first sign of chest pain. Empty the entire powder under your tongue and let it dissolve. Do not swallow or rinse with water.,If pain persists after 5 minutes, take a second packet. If still no relief after 5 more minutes, take a third and call 911.,Sit or lie down when taking this medication to prevent dizziness or fainting.,Avoid alcohol; it may worsen side effects like low blood pressure.,Do not use Viagra, Cialis, Levitra, or other erectile dysfunction drugs while on this medicine—serious drop in blood pressure can occur.,Headaches are common; do not stop taking the medication. Over-the-counter pain relievers may help.,Store packets at room temperature away from moisture and heat. Do not open until ready to use.
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 GONITRO vs ACETAMINOPHEN AND CODEINE PHOSPHATE, answered by our medical review team.
GONITRO is a Nitrate Vasodilator that works by Nitric oxide (NO) donor; activates guanylyl cyclase, increasing c GMP in vascular smooth muscle, leading to vasodilation.. 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 GONITRO 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 GONITRO is: Sublingual: 0.3-0.6 mg at onset of angina, may repeat every 5 minutes up to 3 doses within 15 minutes. Prophylactic: 0.3-0.6 mg 5-10 minutes before activity. Transdermal: Apply 0.2-0.8 mg/hour patch once daily, remove at bedtime to prevent tolerance. Intravenous: Start at 5 mcg/min, titrate by 5-20 mcg/min every 3-5 minutes based on hemodynamic response; usual range 10-200 mcg/min.. 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 GONITRO 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. GONITRO is classified as Category C. FDA Pregnancy Category C. First trimester: no increased risk of major malformations in human studies; animal studies show fetal toxicity at high doses. Second/third trimesters: ris. 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.