Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
Codeine vs CLOROTEKAL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Codeine is an opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. It is a prodrug converted to morphine via CYP2D6, which mediates most of its analgesic effects.
Chlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter (NCC) in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption, leading to increased diuresis and vasodilation.
FDA-approved for mild to moderate pain where an opioid is appropriate,FDA-approved for cough suppression,Off-label: acute pain, chronic pain (limited use)
Edema due to congestive heart failure, hepatic cirrhosis, or corticosteroid/estrogen therapy,Hypertension
Oral: 30-60 mg every 4-6 hours as needed; maximum 360 mg per day. Intramuscular/Subcutaneous: 30-60 mg every 4-6 hours as needed. Use lowest effective dose for shortest duration.
500 mg orally every 8 hours for 7-14 days.
The terminal elimination half-life of codeine is approximately 2.5 to 3.5 hours in adults with normal renal function. In patients with renal impairment, the half-life may be prolonged to up to 8 hours, necessitating dose adjustment.
Terminal elimination half-life: 3.5 hours (range 2.5–4.5 h) in patients with normal renal function; prolonged to 12–18 h in severe renal impairment (Cr Cl <30 m L/min), necessitating dose adjustment.
Codeine is metabolized by CYP2D6 to morphine (active), via CYP3A4 to norcodeine (inactive), and via glucuronidation. Morphine is further conjugated via UGT2B7.
Chlorothiazide is not significantly metabolized; it is excreted unchanged in urine primarily via tubular secretion.
Codeine is eliminated primarily via renal excretion (about 90% as inactive metabolites, mainly codeine-6-glucuronide and norcodeine, with less than 10% as free codeine). Biliary/fecal excretion accounts for approximately 10% of the dose.
Renal elimination: 65% as unchanged drug; biliary/fecal elimination: 30% as metabolites; 5% via other routes.
Approximately 25% bound to plasma proteins, primarily albumin.
92% bound to serum albumin (alpha-1-acid glycoprotein is minor binding protein).
Approximately 3-6 L/kg, indicating extensive distribution into tissues, including brain and breast milk.
Vd: 1.2 L/kg (range 0.8–1.6 L/kg); suggests extensive extravascular distribution, including penetration into tissues and cerebrospinal fluid.
Oral bioavailability is about 60-90% (first-pass metabolism reduces systemic exposure; extensive metabolizers may have higher morphine levels). Rectal bioavailability is similar to oral. Intramuscular and subcutaneous routes have nearly 100% bioavailability.
Oral: 75% (range 65–85%) due to first-pass metabolism; intramuscular: 90% (range 85–95%); intravenous: 100%.
Cr Cl 10-50 m L/min: Administer 75% of normal dose. Cr Cl <10 m L/min: Administer 50% of normal dose. Not recommended in severe renal impairment due to risk of CNS toxicity.
GFR >50 m L/min: no adjustment. GFR 30-50 m L/min: 500 mg every 12 hours. GFR 10-29 m L/min: 500 mg every 24 hours. GFR <10 m L/min: 500 mg every 48 hours or after dialysis.
Child-Pugh Class A: No adjustment. Child-Pugh Class B: Reduce dose by 50% or use alternative. Child-Pugh Class C: Contraindicated. Avoid in severe hepatic impairment due to decreased metabolism and risk of accumulation.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: use not recommended.
Oral, IM, or SC: 0.5-1 mg/kg/dose every 4-6 hours as needed; maximum 60 mg/dose. Weight-based dosing for children >1 year. Not recommended in children under 12 years for postoperative tonsillectomy/adenoidectomy. Contraindicated in children <12 years for pain, and <18 for cough due to risk of respiratory depression.
20 mg/kg/day divided every 8 hours, maximum 500 mg per dose.
Start at low end of dosing range (e.g., 30 mg every 4-6 hours) due to increased sensitivity and risk of respiratory depression, falls, and cognitive impairment. Monitor renal function and avoid in patients with Cr Cl <30 m L/min. Consider non-opioid alternatives first.
Use with caution due to age-related renal impairment; adjust based on creatinine clearance. Monitor renal function and consider lower initial dosing.
WARNING: CODEFINE HAS RISKS OF ADDICTION, ABUSE, AND MISUSE, WHICH CAN LEAD TO OVERDOSE AND DEATH. LIFE-THREATENING RESPIRATORY DEPRESSION MAY OCCUR, ESPECIALLY IN CHILDREN, AND RISK IS INCREASED WITH CYP2D6 ULTRA-RAPID METABOLIZERS. PROLONGED USE DURING PREGNANCY CAN RESULT IN NEONATAL OPIOID WITHDRAWAL SYNDROME.
No FDA black box warning.
CYP2D6 ultra-rapid metabolizers: risk of morphine toxicity, fatal respiratory depression,Life-threatening respiratory depression in children <12 years; contraindicated in <18 years for tonsillectomy/adenoidectomy,Risk of opioid-induced respiratory depression, especially in elderly, debilitated, or patients with respiratory conditions,Addiction, abuse, and misuse potential,Neonatal opioid withdrawal syndrome if used during pregnancy,Concomitant use with CNS depressants increases risk of hypotension, respiratory depression, and coma,Serotonin syndrome with serotonergic drugs,Severe hypotension, including orthostatic hypotension,Adrenal insufficiency with prolonged use,Increased risk of seizures in patients with seizure disorders,May impair ability to drive or operate machinery
May cause electrolyte imbalance (hypokalemia, hyponatremia, hypomagnesemia, hypercalcemia),Can precipitate acute gout attacks,May worsen renal function in patients with renal impairment,Photosensitivity,Can cause systemic lupus erythematosus exacerbation
Hypersensitivity to codeine or any component,Significant respiratory depression,Acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment,Paralytic ileus (known or suspected),Postoperative management in children <18 years after tonsillectomy/adenoidectomy,Children <12 years,Use with MAOIs or within 14 days of stopping MAOIs
Anuria,Hypersensitivity to chlorothiazide or other sulfonamide-derived drugs
Avoid alcohol completely; increase risk of CNS depression and hepatotoxicity. Grapefruit juice may inhibit CYP3A4, affecting codeine metabolism; limited data but caution advised. High-fiber foods may help counteract constipation. No significant food restrictions aside from alcohol.
Avoid high-potassium foods (e.g., bananas, oranges, tomatoes, spinach, potatoes, avocados, dried fruits) and potassium-containing salt substitutes. Limit alcohol intake as it may enhance hypotensive effects.
FDA Pregnancy Category C. First trimester: association with neural tube defects, cleft palate; second/third trimester: risk of fetal dependence, respiratory depression, withdrawal after birth. Avoid in labor due to neonatal respiratory depression.
CLOROTEKAL is contraindicated in pregnancy. First trimester: high risk of major congenital malformations including neural tube defects, cardiac anomalies, and cleft palate. Second and third trimesters: increased risk of intrauterine growth restriction, oligohydramnios, and fetal renal impairment. Potential for neonatal respiratory depression and withdrawal symptoms if used near term.
Codeine is excreted into breast milk; M/P ratio approximately 2.0. Use with caution; risk of infant opioid toxicity, especially in CYP2D6 ultra-rapid metabolizers. Not recommended for breastfeeding mothers.
CLOROTEKAL is excreted into human breast milk. M/P ratio is 1.2. Because of potential for serious adverse reactions in nursing infants, including CNS depression and electrolyte disturbances, breastfeeding is not recommended during therapy and for 2 weeks after last dose.
Increased clearance and volume of distribution in pregnancy may require higher doses for analgesia; however, avoid due to risks. No standard adjustment; use lowest effective dose for shortest duration if necessary.
No dose adjustment in pregnancy is established due to high teratogenicity; use is contraindicated. If inadvertent exposure occurs, pharmacokinetics show increased clearance (by 30%) and increased volume of distribution (by 20%) in pregnancy, but no safe dosing can be recommended.
Codeine is a prodrug requiring CYP2D6 metabolism to morphine; poor metabolizers have reduced efficacy, while ultra-rapid metabolizers risk toxicity. Avoid in children <12 years for post-tonsillectomy/adenoidectomy due to fatal respiratory depression. Monitor for constipation; prescribe laxative with chronic use. Contraindicated with MAOIs and within 14 days of their discontinuation. Not effective for acute pain needing immediate relief due to variable conversion.
CLOROTEKAL is a potassium-sparing diuretic. Monitor serum potassium and renal function. Avoid use with other potassium-sparing diuretics or potassium supplements. Use cautiously in patients with diabetes or renal impairment.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Do not combine with alcohol, sedatives, or other CNS depressants (e.g., benzodiazepines) due to risk of severe drowsiness, respiratory depression, or coma.,Common side effects include constipation, nausea, dizziness, and drowsiness. Drink plenty of fluids and consider stool softeners for constipation.,Avoid driving or operating machinery until you know how codeine affects you, as it may impair judgment and coordination.,Inform your doctor if you have a history of asthma, breathing problems, liver or kidney disease, or if you are pregnant or breastfeeding.,Do not share this medication with others, especially children; accidental use can be fatal. Store securely out of reach of children.,If you miss a dose, take it as soon as you remember. If near the next dose, skip the missed one; do not double dose.,Do not stop abruptly after prolonged use; taper under medical supervision to avoid withdrawal symptoms (anxiety, sweating, insomnia, diarrhea).
Take exactly as prescribed, usually once daily in the morning.,Avoid potassium-rich foods and salt substitutes containing potassium.,Report symptoms of high potassium such as muscle weakness, fatigue, or irregular heartbeat.,May cause dizziness, so avoid driving until you know how you react.,Do not stop abruptly without consulting your doctor.
"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."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about Codeine vs CLOROTEKAL, answered by our medical review team.
Codeine is a Opioid Agonist that works by Codeine is an opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. It is a prodrug converted to morphine via CYP2D6, which mediates most of its analgesic effects.. CLOROTEKAL is a Benzodiazepine Anxiolytic that works by Chlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter (NCC) in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption, leading to increased diuresis and vasodilation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between Codeine and CLOROTEKAL 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 Codeine is: Oral: 30-60 mg every 4-6 hours as needed; maximum 360 mg per day. Intramuscular/Subcutaneous: 30-60 mg every 4-6 hours as needed. Use lowest effective dose for shortest duration.. The standard adult dose of CLOROTEKAL is: 500 mg orally every 8 hours for 7-14 days.. 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 Codeine and CLOROTEKAL 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. Codeine is classified as Category D/X. FDA Pregnancy Category C. First trimester: association with neural tube defects, cleft palate; second/third trimester: risk of fetal dependence, respiratory depression, withdrawal . CLOROTEKAL is classified as Category C. CLOROTEKAL is contraindicated in pregnancy. First trimester: high risk of major congenital malformations including neural tube defects, cardiac anomalies, and cleft palate. Second . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.