CAMBIA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CAMBIA (CAMBIA).
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis and thereby alleviating inflammation, pain, and fever.
| Metabolism | Hepatic metabolism primarily via CYP2C9 and to a lesser extent via CYP3A4 and conjugation (glucuronidation). Active metabolite: diclofenac. |
| Excretion | Approximately 50% of a dose is excreted in urine primarily as metabolites and conjugates, with less than 10% as unchanged drug. Biliary/fecal excretion accounts for about 40%. |
| Half-life | Terminal elimination half-life of diclofenac (active moiety) is approximately 1.9-2.1 hours. The clinical context: short half-life supports twice-daily dosing for acute pain. |
| Protein binding | 99.7% bound to serum albumin, primarily to albumin site II. |
| Volume of Distribution | Approximately 0.12-0.17 L/kg. This low Vd indicates limited extravascular distribution and high plasma protein binding. |
| Bioavailability | Oral bioavailability of diclofenac potassium is approximately 100% (rapidly and completely absorbed). |
| Onset of Action | Oral administration (diclofenac potassium): onset of analgesia within 15-30 minutes. |
| Duration of Action | Analgesic effect lasts approximately 6-8 hours following a single oral dose. |
50 mg orally once daily as needed for acute migraine, maximum 1 packet (50 mg) per 24 hours.
| Dosage form | FOR SOLUTION |
| Renal impairment | Contraindicated in patients with CrCl <30 mL/min. For CrCl 30-59 mL/min, consider alternative therapy; if used, monitor renal function closely. No adjustment for CrCl ≥60 mL/min. |
| Liver impairment | Contraindicated in Child-Pugh class C (severe hepatic impairment). For Child-Pugh class B (moderate), reduce dose to 25 mg orally once daily. No adjustment for Child-Pugh class A. |
| Pediatric use | Not recommended for use in pediatric patients below 18 years of age; safety and efficacy not established. |
| Geriatric use | Start at lowest effective dose (25 mg orally once daily) due to increased risk of gastrointestinal bleeding, renal impairment, and cardiovascular events. Maximum 50 mg per 24 hours, with close monitoring. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CAMBIA (CAMBIA).
| Breastfeeding | Excreted into breast milk in low amounts; M/P ratio not established for diclofenac specifically. Consider risks of infant gastrointestinal and renal adverse effects. Recommend avoiding use in breastfeeding women due to potential for serious adverse reactions in nursing infants. |
| Teratogenic Risk | Pregnancy Category C prior to 30 weeks gestation; Category D starting at 30 weeks gestation. Avoid use during third trimester due to risk of premature closure of ductus arteriosus and oligohydramnios. First and second trimester use only if clearly needed; risk of miscarriage and fetal malformations (cardiac, gastroschisis) may be increased. Not recommended during labor and delivery due to potential for prolonged gestation and uterine inertia. |
■ FDA Black Box Warning
Increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. Increased risk of serious gastrointestinal adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal.
| Serious Effects |
Hypersensitivity to diclofenac or any component, history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs, perioperative pain in the setting of coronary artery bypass graft (CABG) surgery, advanced renal disease, severe hepatic impairment, active gastrointestinal bleeding or perforation, history of recurrent peptic ulcer disease, third trimester of pregnancy.
| Precautions | Cardiovascular risk (avoid in patients with recent CABG), gastrointestinal risk (use lowest effective dose for shortest duration), renal toxicity, hepatic impairment, anaphylactoid reactions, hypertension, fluid retention, masking of infection, avoid use in late pregnancy (arterial duct closure risk). |
| Food/Dietary | Avoid alcohol; may increase GI irritation and bleeding risk. Avoid concurrent use with other NSAIDs, including over-the-counter ibuprofen or naproxen. No specific food restrictions, but taking with food may delay absorption; take on empty stomach for best effect. |
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| Fetal Monitoring | Monitor maternal renal function, hepatic function, and platelet count if prolonged use. Fetal monitoring includes ultrasound for oligohydramnios and ductus arteriosus patency if used after 30 weeks gestation. Assess for fetal growth restriction if used chronically. |
| Fertility Effects | NSAIDs including diclofenac may impair female fertility through effects on ovulation (reversible upon discontinuation). No known adverse effects on male fertility. |
| Clinical Pearls | CAMBIA (diclofenac potassium) is formulated as a powder for oral solution, designed for rapid absorption. Administer on an empty stomach for fastest onset (approx. 15-30 min). Avoid in patients with aspirin-sensitive asthma, recent CABG, or active GI bleeding. Use lowest effective dose, shortest duration. Monitor renal function in elderly, dehydrated, or those on diuretics/ACE inhibitors. |
| Patient Advice | Take this medication on an empty stomach with a full glass of water for fastest relief. · Do not take with alcohol, aspirin, or other NSAIDs to reduce risk of stomach bleeding. · Stop and seek immediate medical help if you experience chest pain, weakness, slurred speech, or signs of allergic reaction (rash, swelling, trouble breathing). · Avoid driving if you feel dizzy or drowsy after taking. · Do not use for more than the prescribed duration; risk of cardiovascular and GI events increases with longer use. |