Nurofen

Active Ingredient & Mechanism of Action

• Active Ingredient: Ibuprofen (some variants contain ibuprofen lysine or sodium, which absorb more rapidly).
• Mechanism: Nurofen works by non-selectively inhibiting the cyclooxygenase enzymes (COX-1 and COX-2):
  1. Inhibition of Prostaglandins: It blocks the conversion of arachidonic acid into prostaglandins—chemical messengers responsible for triggering pain, fever, and localized tissue swelling.
  2. Anti-Inflammatory Effect: By reducing prostaglandin production directly at the site of inflammation or injury, it provides targeted pain relief and eases swelling.

Available Formulations & Variants

• Standard Oral Tablets & Caplets: 200 mg and 400 mg (e.g., Nurofen 200mg, Nurofen Forte 400mg).
• Rapid-Absorbing Formulations: Nurofen Express (containing ibuprofen lysine or sodium for faster absorption and quicker onset of pain relief).
• Targeted Release / Sustained Release: Formulations designed for longer-lasting relief (e.g., Nurofen Zavance or Nurofen Retard).
• Pediatric Formulations (Nurofen for Children): 100 mg / 5 mL and 200 mg / 5 mL sugar-free liquid suspensions (often orange or strawberry flavored), along with soft chewable capsules for older children.
• Topical Formulations: Nurofen Gel (5% ibuprofen) applied directly to the skin for localized joint, tendon, or muscle pain.
• Combination Formulations: Nurofen Plus (combining ibuprofen with codeine) or Nurofen Cold & Flu (combining ibuprofen with phenylephrine or pseudoephedrine).

Clinical Indications

• Headaches & Migraines: Tension headaches, sinus headaches, and acute migraine symptoms.
• Musculoskeletal Pain: Backache, muscular strains, sprains, joint pain, and rheumatic pain.
• Dental & Periodontal Pain: Toothaches and post-dental procedure discomfort.
• Dysmenorrhea: Period pain and menstrual cramps.
• Fever & Symptoms of Cold/Flu: Lowering high body temperature and easing accompanying body aches.

Key Pharmacokinetics

• Absorption: Rapidly absorbed from the gastrointestinal tract. Standard tablets reach peak plasma levels in about 1 to 2 hours, whereas liquid softgel or lysine formulations can achieve peak levels in under 45 minutes.
• Metabolism & Elimination: Extensively metabolized by the liver via CYP2C9 into inactive metabolites. It has a short half-life of approximately 2 hours and is excreted primarily through the kidneys in urine.

Administration Guidelines & Dosage Limits

• Taking with Food: Should ideally be swallowed whole with water after a meal or with food/milk to minimize stomach irritation.
• Standard Adult Dosing: 200 mg to 400 mg taken every 4 to 6 hours as needed.
• Maximum Daily Dose Limits:
  • OTC Maximum: 1,200 mg in 24 hours for adults and children over 12 years (unless supervised by a physician).
• Pediatric Dosing (Nurofen for Children): Dosed strictly based on body weight (typically 5 to 10 mg/kg per dose) every 6 to 8 hours (maximum 30 to 40 mg/kg per day).

Safety Profile & Key Considerations

• Gastrointestinal Caution: Can cause stomach upset, heartburn, nausea, or abdominal pain. Prolonged use or high doses carry a risk of stomach ulcers and gastrointestinal bleeding.
• Cardiovascular & Renal Precautions: Long-term high-dose use increases the risk of high blood pressure, fluid retention, kidney impairment, and cardiovascular events.
• Asthma Warning: Individuals with a history of aspirin-sensitive or NSAID-induced asthma should avoid Nurofen, as it can trigger bronchospasm.
• Pregnancy Warning: Contraindicated during the third trimester of pregnancy (can cause premature closure of the fetal ductus arteriosus and renal complications). Avoid during the first and second trimesters unless specifically advised by a doctor.
• Key Drug Interactions:
  • Aspirin & Blood Thinners (e.g., Warfarin): Significantly elevates the risk of internal bleeding.
  • Antihypertensives & Diuretics: May reduce the blood-pressure-lowering effects of these medications.
  • Other NSAIDs / Corticosteroids: Co-administration with other NSAIDs (e.g., naproxen, diclofenac) increases toxicity risks without added benefit.

Note: Nurofen is an over-the-counter and pharmacy-only medication. Recommended dosage limits, age appropriateness, and individual risk factors (such as a history of ulcers or kidney disease) should be reviewed with a doctor or pharmacist.