INN monograph
Paracetamol / Chlorzoxazone
Non-opioid analgesic / antipyretic · POM
Source-linked · Updated 03 Aug 2026 · Source: Local active-ingredient clinical extract; RxNorm (NLM RxNav); PubChem; Component monographs (multi-source pipeline)
Kenya market
Wholesale / list prices where loaded
Risk first
Contraindications
- [Paracetamol] Severe active hepatic disease / acute liver failure.
- Hypersensitivity.
- Chronic heavy alcohol use — use reduced maximum daily dose or avoid. [Chlorzoxazone] Hypersensitivity to the active substance or excipients.
- Additional absolute contraindications are indication- and product-specific — consult SmPC.
Precautions
- [From component Paracetamol] Risk of severe hepatotoxicity in overdose.
- Chronic high-dose use, malnutrition, enzyme-inducing drugs, and alcohol increase risk.
- Check total daily intake from all sources.
Point of care
Dosing
Adult
Dosing is indication-, age-, weight- and organ-function-specific for this INN. Do not use class averages for high-risk patients. Confirm the exact regimen in the current SmPC and Kenya Standard Treatment Guidelines. Typical professional workflow: (1) confirm indication, (2) check renal/hepatic function, (3) screen interactions/allergies, (4) select dose/route/duration, (5) define monitoring.
Paediatric
Paediatric dosing is weight- and age-based; use a paediatric formulary / SmPC. Do not extrapolate adult tablets without calculation.
Renal
Generally safe; prolonged high dose rare associations — prefer careful use in advanced CKD.
- CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Hepatic
PRIMARY toxicity organ in overdose; therapeutic doses usually safe if daily limits respected.
Safety
Drug interactions
- Fixed-dose/multi-ingredient product.
- Clinical details partially inherited from component monographs: Paracetamol, Chlorzoxazone.
- Confirm combination SmPC for exact dosing.
Safety
Adverse effects
- [Paracetamol] Rare at therapeutic doses.
- Serious: acute liver failure in overdose, rare severe skin reactions (SJS/TEN/AGEP). [Chlorzoxazone] ADVERSE REACTIONS Chlorzoxazone containing products are usually well tolerated.
- It is possible in rare instances that chlorzoxazone may have been associated with gastrointestinal bleeding.
- Drowsiness, dizziness, lightheadedness, malaise, or over-stimulation may be noted by an occasional patient.
- Rarely, allergic type skin rashes, petechiae, or ecchymoses may develop during treatment.
- Angioneurotic edema or anaphylactic reactions are extremely rare.
- There is no evidence that the drug will cause renal damage.
- Rarely, a patient may note discoloration of the urine resulting from a phenolic metabolite of chlorzoxazone.
- This finding is of no known clinical significance.
- To report SUSPECTED ADVERSE EVENTS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800- FDA-1088 or http://www.fda.gov/ for voluntary reporting of adverse reactions.
Use
Indications
- Mild to moderate pain associated with muscle tension.
- Clinical selection for Paracetamol / Chlorzoxazone should follow culture results where relevant, Kenya STG/EML recommendations, and the current product SmPC.
- Class context: Non-opioid analgesic / antipyretic.
- Confirm site-specific dose, duration and monitoring before prescribing.
Pharmacology
Mode of action
Paracetamol is an inhibitor of cyclo-oxygenase [COX-1 and COX-2] enzymes that catalyzes the conversion of arachidonic acid to PGH2 while chlorzoxazone is has antispastic activity.
Full mechanism text
Paracetamol is an inhibitor of cyclo-oxygenase [COX-1 and COX-2] enzymes that catalyzes the conversion of arachidonic acid to PGH2 while chlorzoxazone is has antispastic activity.
ADME
Pharmacokinetics & PD
| Onset | 30–60 minutes oral |
|---|---|
| Duration | 4–6 hours |
| Route | ORAL / RECTAL / IV |
| Metabolism | (glucuronidation/sulfation); toxic NAPQI pathway via CYP2E1 when pathways saturated or glutathione depleted. |
| Half-life | ~2–3 h; prolonged in liver disease/overdose. |
Full PK/PD text
Rapid oral absorption. Hepatic metabolism (glucuronidation/sulfation); toxic NAPQI pathway via CYP2E1 when pathways saturated or glutathione depleted. Half-life ~2–3 h; prolonged in liver disease/overdose.
Kenya
Brands & prices
| Brand | Company | Pack | KES |
|---|---|---|---|
| No brands linked yet. | |||
Special populations
Pregnancy & lactation
Pregnancy
[Paracetamol] Analgesic/antipyretic of choice in pregnancy when needed; use lowest effective dose/shortest duration. [Chlorzoxazone] Use only if potential benefit justifies potential risk; prefer agents with better reproductive data when alternatives exist.
Lactation
Compatible with breastfeeding at standard doses.
Diet
Food & alcohol
- Food
- Food
Trust
Sources & disclaimer
Source: Local active-ingredient clinical extract; RxNorm (NLM RxNav); PubChem; Component monographs (multi-source pipeline)
Clinical review date not recorded.
Decision support only — not a substitute for clinical judgment, product SmPC, or Kenya STG/EML.