Flurbiprofen

Flurbiprofen is a non-steroidal anti-inflammatory drug (NSAID) used to reduce pain, inflammation, and fever. It works by inhibiting COX enzymes, which are involved in producing prostaglandins, the chemicals that cause inflammation and pain. Approved in the 1970s, flurbiprofen is used for conditions like arthritis and musculoskeletal pain. However, it carries risks such as gastrointestinal and cardiovascular side effects with long-term use.

MECHANISM OF ACTION

Flurbiprofen works by blocking the cyclooxygenase (COX) enzymes, which are involved in the production of prostaglandins chemicals that trigger pain, inflammation, and fever. There are two types of COX enzymes:

COX-1: Found throughout the body, COX-1 helps protect the stomach lining and supports kidney function.

COX-2: Primarily activated during inflammation, COX-2 produces prostaglandins that cause pain and swelling.

Flurbiprofen inhibits both COX-1 and COX-2, with a stronger effect on COX-1. By reducing prostaglandin production, flurbiprofen helps to alleviate pain, inflammation, and fever. However, inhibiting COX-1 can also lead to side effects, such as stomach irritation and ulcers.

PHARMACOKINETICS

Absorption:

After oral administration, flurbiprofen is quickly absorbed, reaching peak plasma levels within 1–2 hours. Its bioavailability is about 80%, and while food may slightly delay absorption, it doesn't significantly impact the total absorption rate.

Distribution:

The drug is extensively distributed throughout the body, including in joint fluid, which helps it target inflammation. It is highly bound to plasma proteins (about 99%), mainly albumin.

Metabolism:

Flurbiprofen is metabolized in the liver by cytochrome P450 enzymes into inactive metabolites, which are then excreted by the kidneys. Its half-life ranges from 3 to 6 hours, varying by individual.

Excretion:

The drug and its metabolites are mainly eliminated through urine, with a small amount excreted in feces. This pharmacokinetic profile allows for effective pain and inflammation relief with regular dosing.

DOSAGE AND ADMINISTRATION

Flurbiprofen dosage depends on the condition and form:

Oral (adults): Typically 100-200 mg per day, divided into 2-3 doses, with a maximum of 300 mg daily.

Topical: Apply 0.03% gel to the affected area 3-4 times a day.

Ocular: Use 1 drop of the 0.03% solution in the affected eye every 4-6 hours.

It can be taken with food to reduce stomach irritation. Dose adjustments may be needed for the elderly or those with kidney/liver issues.

DRUG INTERACTIONS

Flurbiprofen may interact with several drugs, including:

• Other NSAIDs: Increases the risk of gastrointestinal issues and kidney damage.
• Anticoagulants: Raises bleeding risk.
• Antihypertensives: May reduce blood pressure medication effectiveness and harm kidneys.
• Lithium: Increases lithium toxicity.
• Methotrexate: Can raise toxicity risk, particularly for the kidneys.
• Corticosteroids: Heightens risk of gastrointestinal problems.
• Cyclosporine: Increases kidney damage risk.

CONTRAINDICATIONS

• Hypersensitivity:

If you are allergic to flurbiprofen or other NSAIDs (e.g., aspirin), it should not be used

• Active Gastrointestinal Bleeding or Ulcers:

Flurbiprofen can worsen bleeding and increase the risk of ulcers.

• Severe Kidney or Liver Impairment:

Flurbiprofen should be avoided in patients with severe renal or hepatic dysfunction.

• Pregnancy (Third Trimester):

It is contraindicated during the third trimester due to the risk of affecting fetal development and premature closure of the ductus arteriosus.

• Asthma (related to NSAIDs):

In patients with NSAID-induced asthma, flurbiprofen should be avoided.

SIDE EFFECTS

Common side effects of flurbiprofen include:

• Gastrointestinal issues (Stomach pain, nausea, indigestion, ulcers, and gastrointestinal )
• bleeding
• Headache
• Dizziness
• Rash

Serious side effects (less common but more severe) include:

• Kidney problems (Reduced kidney function or failure)
• Heart issues (Increased risk of heart attack, stroke, and high blood pressure)
• Liver problems (Jaundice, liver damage)
• Allergic reactions (Swelling, difficulty breathing, or skin rashes)

TOXICITY

Flurbiprofen toxicity can occur if taken in excessive amounts and may cause:

• Gastrointestinal issues: Severe stomach pain, ulcers, and bleeding.
• Kidney damage: Decreased kidney function or failure.
• Central nervous system effects: Dizziness, confusion, and seizures.
• Respiratory issues: Difficulty breathing, especially in severe cases.
• Cardiovascular problems: Increased risk of heart attack or stroke.