Definition & Overview

The term NSAIDs stands for non-steroidal anti-inflammatory drugs. They are a class of non-opioid analgesic medications that are primarily used to relieve pain, fever and inflammation. Ibuprofen and aspirin are some of the most commonly known examples.

 

NSAIDS come as:

• Tablets.
• Gels.
• Creams.
• Capsules.’
• Suppositories.
• Injections.

Dosages of these drugs are to be determined by a qualified health specialist.

Several NSAIDs can be obtained over the counter. These include:

• Aspirin (acetyl salicylic acid).
• Ibuprofen.
• Naproxen.

 

This article focuses on mentioning and/or discussing their classification, uses, mechanism of action, associated adverse effects, contraindications.

 

Classification

Nonselective COX inhibitors (traditional NSAIDs)

• Salicylates: Aspirin.
• Propionic acid derivatives: Ibuprofen, Naproxen, Ketoprofen, Flurbiprofen.

• Fenamate: Mephenamic acid.
• Enolic acid derivatives: Piroxicam, Tenoxicam.

• Acetic acid derivatives: Ketorolac, Indomethacin, Nabumetone

• Pyrazolone derivatives: Phenylbutazone, Oxyphenbutazone.

 

Preferential COX-2 inhibitors

Nimesulide, Diclofenac, Aceclofenac, Meloxicam, Etodolac.

 

 Selective COX-2 inhibitors

Celecoxib, Etoricoxib, Parecoxib, Rofecoxib, Valdecoxib.

 

Analgesic-antipyretics with poor antiinflammatory action

• Paraaminophenol derivative: Paracetamol (Acetaminophen).

• Pyrazolone derivatives: Metamizol (Dipyrone), Propiphenazone.

• Benzoxazocine derivative: Nefopam

 

 

Indications/Uses

NSAIDs can be used as:

• Anti-inflammatory agents.
• Analgesc drugsa.
• Antipyretic agents.

 

They are used in:

• Dysmenorrhea.
• Parturition. NSAIDs have the potential to delay and retard labour.
• Arthritic conditions.
• Muscle pain.
• Gout.

NSAIDs can also be used as anti-platelet aggregatory agents. NSAIDs inhibit synthesis of both proaggregatory (TXA2) and antiaggregatory (PGI2) prostanoids, but effect on platelet TXA2 (COX-1 generated) predominates→ therapeutic doses of most NSAIDs inhibit platelet aggregation: bleeding time is prolonged.

 

MoA

Mechanism of action (MoA) of NSAIDs

They work by blocking prostaglanding production.

NSAIDs work according to their categorization.

Non-selective COX inhibitors

Their main mechanism of action is COX inhibition. COX is cyclooxygenase enzyme. It converts arachidonic acid into:

•  Thromboxanes.
• Prostacyclins.
•  Prostaglandins.

 

Therefore, NSAIDs inhibit COX enzyme and block formation of the above mentioned  products.

Two isoenzymes of COX are COX-1 and  COX-2. most of the NSAIDs are non-selective COX inhibitors; they inhibit both isoenzymes.

 

Interactions

Some NSAIDs have interactions with other agents. This phenomenon is called drug-drug intearactions (DDIs). This can affect the efficacy of medicines either positively or negatively.

It is a crucial step to receive medical advice from your health-care practioner if before taking or receiving NSAIDs if already you are on:

• Warfarin or low-dose aspirin for preventing blood clotting activity.
• Diuretics for treatment of hypertension.
• Lithium for treatment of mental conditions such as bipolar disorder.
• Methotrexate to treat rheumatoid arthritis.
• Ciclosporin for auto-immune conditions.
• Selective serotonin reuptake inhibitors (SSRIs) for treating depression.

 

 Adverse Effects

NSAIDs can affect various body systems such as the following:

• Gastrointestinal system.
• Renal system.
• Cardiovascular system.
• Hematologic system.
• Hepatic system..

 

Gastrointestinal system

COX-1 inhibitors prevent formation of prostaglandins which are gastro-protective (they protect the gastric mucosa). There is a higher risk of injury in patients with a history of peptic ulcer disease. NSAID toxicity can manifest as gastro-intestinal bleeding.

 

Renal system

Both COX-2 and COX-2 enzymes are involved in production of prostaglandins that are involved in renal physiology. In renal dysfunction, NSAID reduction of prostaglandins can be a cause of several problems. Complications that can be induced by NSAIDs include;

• Acute renal dysfunction.
• Electrolyte imbalances.
• Nephrotic syndrome.

 

Cardiovascular system

Use of NSAIDs raises the risk of adverse cardiovascular events in patients. These adverse effects include;

• Atrial fibrillation.
• Thromboembolic disorders.
•  Myocardial infarction.

 

Hematologic system

Some NSAIDS such as non-selective NSAIDs for example aspirin posses an anti-platelet activity, which can be problematic if the patient has a history of gastro-intestinal ulcers and conditions that impair platelet activity such as hemophilia and von Willebrand disease.

 

Hepatic system

Rarely do NSAIDs lead to hepatic adverse effects. If they occur, they may be;

• Liver-related hospitalization.
• Hepatotoxicity.

 

Risks

If you currently qualify for any of the following conditions, you should consult your physician about NSAIDs before taking them:

• Carrying a pregnancy.
• Have a history of ulcers.
• Having conditions such as asthma or high blood pressure.
• Age. Being 65 years and above.

 

 Contraindications

NSAIDs are contraindicated in:

• Third trimester of pregnancy.
• Persons who exhibit hypersensitivity reactions to NSAIDs.