Can allopurinol cause a cough?

Allopurinol and Cough: Evidence Assessment

Based on the available evidence, there is no direct indication that allopurinol commonly causes cough as a side effect. While allopurinol is associated with several well-documented adverse reactions, cough is not specifically listed among its common or significant side effects in the available guidelines.

Known Adverse Effects of Allopurinol

Allopurinol is associated with several important adverse effects that clinicians should be aware of:

Severe Hypersensitivity Reactions

• Allopurinol Hypersensitivity Syndrome (AHS) - potentially life-threatening with 25% mortality rate 1, 2
• Manifestations include:
  • Erythematous desquamating rash
  • Fever
  • Hepatitis
  • Eosinophilia
  • Worsening renal function
  • Stevens-Johnson syndrome (SJS)
  • Toxic epidermal necrolysis (TEN)
  • Drug reaction with eosinophilia and systemic symptoms (DRESS) 3

Common Adverse Effects

• Skin reactions (0.8-2.1% of recipients) 4:
  • Pruritus
  • Maculo-papular erythema
  • Urticaria
  • Ichthyosis
• Gastrointestinal symptoms (nausea) 1

Risk Factors for Adverse Reactions

The risk of developing adverse reactions to allopurinol is increased in patients with:

• HLA-B*58:01 genetic variant (particularly in East Asian populations) 1, 2
• Renal impairment 1, 2, 5
• Concomitant use of thiazide diuretics 2, 6
• Concomitant use of ampicillin/amoxicillin (increased risk of skin rash) 2, 6

Clinical Implications and Monitoring

When prescribing allopurinol, clinicians should:

1. Consider genetic testing for HLA-B*58:01 in high-risk populations (Korean, Han-Chinese, Thai descent) 1, 2
2. Start with lower doses in patients with renal impairment 1, 2
3. Slowly titrate the dose to minimize adverse reactions 1
4. Monitor for early signs of hypersensitivity reactions 2
5. Adjust dosing when used with interacting medications (azathioprine, 6-mercaptopurine) 2, 5

Conclusion Regarding Cough

While the evidence thoroughly documents various adverse effects of allopurinol, cough is not specifically mentioned as a recognized side effect in any of the provided guidelines or research evidence. The focus of adverse effect monitoring should remain on the well-established reactions, particularly hypersensitivity reactions that can significantly impact morbidity and mortality.

If a patient develops a cough while taking allopurinol, clinicians should consider other potential causes rather than assuming it is medication-related, while still monitoring for early signs of more serious hypersensitivity reactions that could affect multiple organ systems.