Celecoxib

Uses

Celecoxib used for relief of the signs and symptoms of osteoarthritis, for relief of the signs and symptoms of rheumatoid arthritis; for relief of pain after dental extraction; for reduction of colorectal polyps in Familial Adenomatous Polyposis (FAP)

Celecoxib is also used to associated treatment for these conditions: Ankylosing Spondylitis (AS), Osteoarthritis (OA), Pain, Acute, Primary Dysmenorrhoea, Rheumatoid Arthritis, Rheumatoid Arthritis, Juvenile

How Celecoxib works

Unlike most NSAIDs, which inhibit both types of cyclooxygenases (COX-1 and COX-2), celecoxib is a selective noncompetitive inhibitor of cyclooxygenase-2 (COX-2) enzyme. COX-2 is expressed heavily in inflamed tissues where it is induced by inflammatory mediators. The inhibition of this enzyme reduces the synthesis of metabolites that include prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane (TXA2), prostaglandin D2 (PGD2), and prostaglandin F2 (PGF2). Resultant inhibition of these mediators leads to the alleviation of pain and inflammation.

By inhibiting prostaglandin synthesis, non-steroidal anti-inflammatory drugs (NSAIDs) cause mucosal damage, ulceration and ulcer complication throughout the gastrointestinal tract. Celecoxib poses less of an ulceration risk than other NSAIDS, owing to its decreased effect on gastric mucosal prostaglandin synthesis when compared to placebo.

Celecoxib exerts anticancer effects by binding to the cadherin-11 (CDH11)protein, which is thought to be involved in the progression of tumors, and inhibiting the 3-phosphoinositide-dependent kinase-1 (PDK-1) signaling mechanism. In addition, celecoxib has been found to inhibit carbonic anhydrase enzymes 2 and 3, further enhancing its anticancer effects.

As mentioned in the pharmacodynamics section of this drug entry, celecoxib may cause an increased risk of thrombotic events. The risk of thrombosis resulting from COX-2 inhibition is caused by the vasoconstricting actions of thromboxane A2, leading to enhanced platelet aggregation, which is uncontrolled when the actions of prostacyclin, a platelet aggregation inhibitor, are suppressed through the inhibition of COX-2.

Dosage

Celecoxib dosage

Osteoarthritis: The recommended oral dose is 200 mg per day administered as a single dose or as 100 mg twice daily.

Rheumatoid arthritis: The recommended oral dose is 100 to 200 mg twice daily.

Familial adenomatous polyposis (FAP): The recommended oral dose is 400 mg twice daily to be taken with food.

Dental pain: Single dose of Celecoxib 100 mg to400 mg

Side Effects

Gastrointestinal side effects include abdominal pain, diarrhoea, dyspepsia, flatulence and nausea. Central nervous system side effects include dizziness, headache and insomnia. Other side effects include upper respiratory tract infection, skin rash, back pain and peripheral edema.

Toxicity

The oral TDLo in humans 5.71 mg/kg.

It is not advisable to administer celecoxib in patients with renal impairment or advanced hepatic impairment, as this may lead to increased serum concentrations, causing toxicity. Symptoms of overdose may include breathing difficulties, coma, drowsiness, gastrointestinal bleeding, high blood pressure, kidney failure, nausea, sluggishness, stomach pain, and vomiting. Because serious gastrointestinal tract ulceration and bleeding can occur without preceding symptoms, patients should be monitored for signs/symptoms of gastrointestinal bleeding. Symptomatic and supportive measures should be taken in a celecoxib overdose. The induction of emesis or administration of active charcoal should take place if the patient is seen within 4 hours of celecoxib ingestion. Diuresis, urinary alkalinization, hemodialysis, or hemoperfusion may not be useful in a celecoxib overdose due to its high level of protein binding.

Precaution

Celecoxib cannot be expected to substitute for corticosteroids or to treat corticosteroid insufficiency. Patients on prolonged corticosteroid therapy should have their therapy tapered slowly if a decision is made to discontinue corticosteroids. Celecoxib should be prescribed with extreme caution in patients with a prior history of G.I. ulcer-disease or G.I. bleeding, hepatic and renal insufficiency, heart failure, those taking diuretics and ACE inhibitors, pre-existing asthma, elderly patients.

Interaction

Furosemide: NSAIDs can reduce the matriuretic effect of furosemide and thiazides in some patients.

Fluconazole: Concomitant administration of fluconazole at 200 mg QD resulted in a two-fold increase in celecoxib plasma concentration.

Warfarin: Caution should be exercised when administering Celecoxib with warfarin since these patients are at increased risk of bleeding complications.

Food Interaction

• Avoid alcohol. Alcohol increases the risk of gastrointestinal irritation.
• Avoid multivalent ions. Separate the administration of aluminum and magnesium containing drugs by several hours.
• Take with or without food. Doses up to 200 mg can be taken without regard to food, but doses of 400mg or higher should be taken with food.

Celecoxib Hypertension interaction

[Moderate] Nonsteroidal anti-inflammatory drugs (NSAIDs), including topicals, can lead to new onset of hypertension or worsening of preexisting hypertension, either of which can contribute to the increased incidence of cardiovascular events.

NSAIDs should be used with caution in patients with hypertension.

Blood pressure should be monitored closely during the initiation of NSAID therapy and throughout the course of therapy.

Celecoxib Drug Interaction

Moderate: duloxetine, duloxetine, metoprolol, metoprololUnknown: omega-3 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, pregabalin, pregabalin, acetaminophen, acetaminophen, acetaminophen, acetaminophen, cyanocobalamin, cyanocobalamin, ascorbic acid, ascorbic acid, cholecalciferol, cholecalciferol, cetirizine, cetirizine

Celecoxib Disease Interaction

Major: asthma, GI toxicity, rash, renal toxicities, thrombosisModerate: anemia, heart failure, hepatotoxicity, hyperkalemia, hypertension

Volume of Distribution

The apparent volume of distribution of celecoxib at steady state (Vss/F) is about 429 L, which suggests wide distribution into various tissues. Celecoxib is not preferentially bound to red blood cells. Another resource reports a volume of distribution of 455 ± 166L.

Elimination Route

Celecoxib is absorbed rapidly in the gastrointestinal tract. When a single oral dose of 200 mg was given to healthy research subjects, the peak plasma levels of celecoxib occurred within 3 hours. The Cmax is 705 ng/mL. When multiple doses are given, steady-state concentrations are reached on or before day 5. When taken with a high-fat meal, peak plasma levels are delayed for about 1 to 2 hours with an increase in total absorption (AUC) of 10% to 20%. The AUC of celecoxib has been shown to be significantly lower in patients with chronic renal impairment. A meta-analysis of pharmacokinetic studies has suggested an approximately 40% higher AUC (area under the curve) of celecoxib in black patients compared to Caucasians for unknown reasons.

Half Life

The effective half-life of celecoxib is approximately 11 hours when a single 200 mg dose is given to healthy subjects. The terminal half-life of celecoxib varies because of its low solubility, which prolongs absorption.

Clearance

Apparent clearance (CL/F), single oral 200 mg dose, healthy subjects = 27.7 L/hr. Clearance may be decreased by about 47% in patients with chronic renal insufficiency, according to a pharmacokinetic study. Studies have not been performed in patients with severe renal impairment.

Elimination Route

Celecoxib is primarily eliminated by hepatic metabolism with small amounts (12 About 57% of an oral dose of celecoxib is excreted in the feces and 27% is found to be excreted into the urine in the form of metabolites. The main metabolite in urine and feces is identified as the carboxylic acid metabolite (73%). The amount of glucuronide in the urine is reported to be low.

Pregnancy & Breastfeeding use

Celecoxib should be used during pregnancy only if the potential benefit justifies the potential risk to fetus. But in late pregnancy Celecoxib should be avoided because it may cause premature closure of ductus arteriosus.

It is not known whether Celecoxib is excreted in human milk. Because many drugs are excreted in human milk and because of potential for serious adverse reactions in nursing infants from Celecoxib, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Contraindication

Celecoxib is contraindicated in patients with known hypersensitivity to Celecoxib, who have demonstrated allergic type reactions to sulfonamide or who have experienced asthma, urticaria or allergic type reactions after taking aspirin or other NSAIDs.

Special Warning

Geriatric: Dose adjustment in the elderly is not generally necessary. However, for patients of less than 50 kg in body weight, initiate therapy at the lowest recommended dose.

Paediatric: The safety and efficacy of Celecoxib is not established in paediatric patients.

Hepatic insufficiency: Celecoxib should be introduced at a reduced dose in patients with moderate hepatic impairment. The use of Celecoxib in patients with severe hepatic impairment is not recommended.

Acute Overdose

Patients should be managed by symptomatic and supportive care following an NSAID overdose. No specific antidote is available.

Storage Condition

Store at 15 to 30° C.

Innovators Monograph

You find simplified version here Celecoxib