What are the potential throat side effects of ivermectin and how can they be managed?

Ivermectin and Throat Side Effects

Throat-specific side effects are not documented as a recognized adverse effect of ivermectin in current medical guidelines or clinical literature.

Documented Side Effects of Ivermectin

The established side effect profile of ivermectin does not include throat symptoms. Based on comprehensive guideline reviews, the documented adverse effects are:

Common Side Effects

• Gastrointestinal symptoms: Nausea, abdominal pain, diarrhea, vomiting, and anorexia 1
• Neurological symptoms: Dizziness, drowsiness, and headache 1
• Dermatological reactions: Pruritus, rash, and urticaria 1
• Systemic symptoms: Fever and muscle/joint pain 1

Serious Adverse Events

• Drug discontinuation: Ivermectin probably increases the risk of serious adverse events leading to treatment discontinuation (moderate certainty evidence) 1
• Neurotoxicity risk: Particularly in patients with severe liver disease, where the safety of multiple doses is not well established 1, 2
• Mazzotti reaction: In patients with unsuspected onchocerciasis or other filarial infections, characterized by fever, urticaria, tender lymphadenopathy, and potential respiratory symptoms including asthma exacerbation 1

Clinical Context and Mechanism

Ivermectin acts on chloride-dependent channels and is generally well-tolerated in humans due to P-glycoprotein protection at the blood-brain barrier 3. The side effects that do occur are typically:

• Mild and short in duration after therapeutic oral use 3
• Related to parasite death: Most adverse effects result from inflammatory reactions to antigen release from dying parasites rather than direct drug toxicity 4

Important Caveats

Respiratory Symptoms in Specific Contexts

While throat symptoms are not listed, respiratory manifestations can occur in certain situations:

• Parasitic hypersensitivity reactions: In tropical pulmonary eosinophilia or Loeffler's syndrome, patients may experience cough, wheeze, and dyspnea, but these are disease-related rather than drug-induced 1
• Mazzotti reactions: Can include asthma-like symptoms in patients with underlying filarial infections 1

Drug Interactions and Precautions

• Take with food: Bioavailability increases with food intake, which enhances drug penetration 1
• Avoid alcohol: Reported to worsen side effects 1
• P-glycoprotein interactions: Azithromycin can significantly increase serum ivermectin concentrations, potentially increasing toxicity risk 1

Management Approach

If a patient reports throat symptoms while taking ivermectin:

1. Consider alternative diagnoses: The symptom is likely unrelated to ivermectin and may represent concurrent illness
2. Evaluate for hypersensitivity: Rule out allergic reactions (rash, urticaria, systemic symptoms) 1
3. Assess for underlying parasitic disease: In endemic areas, respiratory symptoms may indicate parasitic lung involvement requiring specialist consultation 1
4. Review medication list: Check for P-glycoprotein inhibitors that could increase ivermectin levels 3