Model Answer
0 min readIntroduction
Pharmacotherapy forms a cornerstone of modern medicine, and a thorough understanding of drug properties is crucial for safe and effective patient care. Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, and Chloroquine, an antimalarial and immunomodulatory drug, represent distinct classes of medications with varied applications. While Celecoxib is primarily used for managing pain and inflammation, Chloroquine has historically been vital in malaria treatment and is now explored for autoimmune conditions. This answer will detail the therapeutic indications, drug interactions, and side effects of each drug, providing a comprehensive overview for medical professionals.
(i) Celecoxib
Celecoxib is a nonsteroidal anti-inflammatory drug (NSAID) belonging to the coxib class. It selectively inhibits cyclooxygenase-2 (COX-2) enzyme, reducing prostaglandin synthesis.
Therapeutic Indications
- Osteoarthritis: Relief of pain and inflammation associated with osteoarthritis.
- Rheumatoid Arthritis: Management of symptoms in rheumatoid arthritis.
- Acute Pain: Short-term treatment of acute pain, including dysmenorrhea (menstrual cramps).
- Ankylosing Spondylitis: Reduction of pain and stiffness in ankylosing spondylitis.
- Familial Adenomatous Polyposis (FAP): Reduction in the number of colorectal polyps in patients with FAP (under specialist supervision).
Drug Interactions
- Aspirin: Concurrent use may reduce the cardioprotective effects of aspirin.
- Warfarin: Increased risk of bleeding due to synergistic effects on platelet function.
- ACE Inhibitors & ARBs: May reduce the antihypertensive effect and potentially increase the risk of renal impairment.
- Diuretics: Increased risk of renal impairment, especially in patients who are volume-depleted.
- Lithium: Celecoxib can increase lithium levels, potentially leading to lithium toxicity.
Side Effects
- Cardiovascular: Increased risk of cardiovascular events (myocardial infarction, stroke), particularly in patients with pre-existing cardiovascular disease.
- Gastrointestinal: Although COX-2 selective, gastrointestinal side effects like dyspepsia, nausea, and abdominal pain can occur. Lower risk of ulcers compared to non-selective NSAIDs.
- Renal: Renal impairment, especially in patients with pre-existing renal disease or those taking diuretics.
- Hepatic: Rarely, liver enzyme elevations.
- Allergic Reactions: Skin rash, pruritus, and rarely, anaphylaxis.
(ii) Chloroquine
Chloroquine is a 4-aminoquinoline derivative historically used as a primary treatment for malaria. It also possesses immunomodulatory properties.
Therapeutic Indications
- Malaria: Treatment and prophylaxis of malaria (particularly Plasmodium vivax). Resistance is a growing concern in many regions.
- Rheumatoid Arthritis: Used as a disease-modifying antirheumatic drug (DMARD) in rheumatoid arthritis.
- Systemic Lupus Erythematosus (SLE): Management of SLE symptoms, including skin rashes, joint pain, and fatigue.
- Amebiasis: Treatment of extraintestinal amebiasis.
- COVID-19 (Historically): Initially investigated as a potential treatment for COVID-19, but subsequent studies showed limited efficacy and potential for harm.
Drug Interactions
- Hydroxychloroquine: Additive cardiotoxicity when used concurrently.
- Digoxin: Chloroquine can increase digoxin levels, potentially leading to digoxin toxicity.
- Antacids: Reduce chloroquine absorption.
- Warfarin: May potentiate the effects of warfarin, increasing the risk of bleeding.
- QT-prolonging drugs: Increased risk of Torsades de Pointes (a life-threatening arrhythmia).
Side Effects
- Ocular: Retinopathy (damage to the retina) with long-term use, potentially leading to irreversible vision loss. Regular ophthalmological monitoring is crucial.
- Cardiovascular: QT prolongation, cardiomyopathy, and arrhythmias.
- Gastrointestinal: Nausea, vomiting, diarrhea, and abdominal pain.
- Neurological: Headache, dizziness, seizures (rare).
- Dermatological: Pruritus, skin rash, and rarely, Stevens-Johnson syndrome.
- Hematological: Hemolytic anemia (particularly in individuals with G6PD deficiency).
Conclusion
Both Celecoxib and Chloroquine are valuable medications with distinct therapeutic roles. However, their use necessitates careful consideration of potential drug interactions and side effects. Celecoxib’s cardiovascular risks and Chloroquine’s ocular and cardiac toxicities require vigilant monitoring. The evolving understanding of drug safety and efficacy, particularly in the context of emerging diseases like COVID-19, underscores the importance of evidence-based medicine and continuous professional development for healthcare providers.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.