Ibuprofen
Ibuprofen
Generic Name
Ibuprofen
Brand Names
Motrin® / Brufen®) is a non‑selective, non‑steroidal anti‑inflammatory drug (NSAID) widely used for pain, inflammation, and antipyretia. Below is a concise, reference‑friendly drug card suitable for medical students, residents, and clinical pharmacists.
Mechanism
- Cyclooxygenase (COX) Inhibition
- *COX‑1* and *COX‑2* enzymes catalyze conversion of arachidonic acid to prostaglandins.
- Ibuprofen competitively and reversibly blocks the active sites of both COX isoforms.
- Result: ↓ prostaglandin synthesis → reduced inflammation, vasodilation, pain, and fever.
- Additional Effects
- Decreases platelet aggregation modestly (via COX‑1 inhibition).
- Modestly affects leukotriene pathways indirectly through reduced prostaglandin E₂ levels.
Pharmacokinetics
| Parameter | Key Data |
| Absorption | Oral: ~80 % bioavailability; peak plasma 1–2 h. |
| Distribution | Volume of distribution 0.15–0.35 L/kg; 99 % plasma protein‑bound (mainly albumin). |
| Metabolism | Hepatic via UDP‑glucuronosyltransferases → mainly 2′-hydroxy‑ibuprofen; minimal CYP involvement. |
| Excretion | Urine (70–80 %), bile (20–30 %). |
| Half‑life | 2–4 h (single dose), 4–6 h with repeated dosing due to accumulation. |
| Special Populations | Children: same PK but dose‑adjusted; renal/hepatic impairment ⇒ reduced clearance, lengthened half‑life. |
Indications
- Acute pain: dental, musculoskeletal, post‑operative.
- Low‑grade fever and inflammatory conditions.
- Rheumatoid arthritis, osteoarthritis, ankylosing spondylitis.
- Dysmenorrhea, migraine (short‑term).
- Low‑dose prophylaxis in certain post‑operative scenarios (e.g., hip arthroplasty pain managed with multimodal analgesia).
> OTC Use – Available 200‑400 mg tablets and 100 mg oral suspension for self‑medication.
Contraindications
| Category | Key Points |
| Absolute Contraindications | Known hypersensitivity to ibuprofen, NSAIDs, or any ingredient. |
| Gastro‑intestinal | Active ulcer, GI bleeding, severe GERD, uncontrolled gastric varices. |
| Cardiovascular | Recent myocardial infarction or unstable angina; uncontrolled hypertension. |
| Renal | Severe renal insufficiency (creatinine >1.5 mg/dL or oliguria). |
| Hepatic | Severe liver disease (Child‑Pugh B/C). |
| Pregnancy | 3rd trimester (risk of premature ductus arteriosus constriction). |
| Children | risks.
• Drug Interactions
• Anticoagulants (warfarin, DOACs) → ↑ bleeding risk.
• ACE inhibitors, ARBs, diuretics → further renal compromise.
• Corticosteroids → additive GI toxicity.
• Others: SSRIs, lithium (↑ serum levels).
Dosing
| Population | Loading Dose | Maintenance | Max Daily |
| Adults & Adolescents | 200–400 mg PO (twice daily) | 200–400 mg PO q6–8 h as needed | 1200 mg/day |
| Children (≥5 yrs, ≥3 kg) | 5 mg/kg PO dosing q6–8 h | Up to 10–15 mg/kg/day | 4–5 mg/kg/QD |
| **Pediatric 7 days unless under prescription supervision.
Adverse Effects
| Serious | Common (Incidence) |
| GI bleeding (0.1–0.5 %) | Nausea, dyspepsia, abdominal cramps |
| Renal impairment/oliguria (1–2 %) | Rash, pruritus, photosensitivity |
| Hypersensitivity (1–3 %) | Dizziness, headache, tinnitus |
| Allergic reactions (anaphylaxis) | Hypothermia (rare) |
• Rare – Stevens–Johnson syndrome, eosinophilic granulomatosis with polyangiitis.
Monitoring
- Baseline: CBC, CMP (renal & hepatic), BP.
- During therapy (≥7 days): Renal function tests (CrCl), liver enzymes, periodic CBC if high dose.
- In high‑risk patients:
- Monitor urinary output, serum creatinine daily for 72 h after first dose.
- Periodic endoscopy in patients with peptic ulcer disease or ongoing GI symptoms.
- Pregnancy: Avoid in 3rd trimester; monitor fetal heart rate if therapy cannot be avoided.
Clinical Pearls
- Maximize efficacy, minimize harm: Always serve ibuprofen with a beverage and a snack; this significantly lowers the incidence of gastric irritation and improves tolerance.
- COX‑2 activity matters: Ibuprofen’s equal inhibition of COX‑1 and COX‑2 makes it more likely to cause GI and platelet side effects than selective COX‑2 inhibitors (e.g., celecoxib).
- Avoid the “aspirin trap”: When taken concurrently with aspirin, ibuprofen can inhibit acetylation of COX‑1, thereby reducing aspirin’s antiplatelet effect. Give ibuprofen 2 h after aspirin for cardiovascular protection or vice‑versa (aspirin >1 h before ibuprofen) to avoid interference.
- Renal caution in the elderly: Even standard therapeutic doses (≤1200 mg/day) can precipitate acute interstitial nephritis or worsening chronic kidney disease if baseline GFR < 60 ml/min/1.73 m².
- Use in asthma with caution: Children with mild asthma tolerate ibuprofen, but adults with severe asthma may experience bronchospasm; consider acetaminophen or a different NSAID if possible.
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• References (abridged, commonly cited sources)
1. Katzung BG, Trevor AJ. *Basic & Clinical Pharmacology*, 15th ed. 2021.
2. WHO. “Non‑Steroidal Anti‑inflammatory Drugs: Pharmacology & Safety.” 2023.
3. Medscape. “Ibuprofen — Drug Information, Indications, Contraindications.” 2024.
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