Gastrointestinal Toxicity

Hydroxychloroquine can cause nausea, vomiting and diarrhoea. However these are most common during the first six weeks of therapy and usually resolve with dose adjustment or medication cessation¹. Nausea and vomiting are induced by direct irritation of the gastric mucosa by hydroxychloroquine, combined with the activation of chemoreceptor trigger zone in the brain that is responsible for vomiting².

Some patients also report:

• Heartburn

• Anorexia

• Distension of the abdomen¹

Specific Effects on the Liver

There are several reports of elevated transaminases with hydroxychloroquine use, particularly patients with acute porphyrias and / or pre-existing liver disease^1,3. However, transaminase levels usually return to baseline levels following the discontinuation of hydroxychloroquine⁴.

Sudden hepatic failure is a small but significant risk in patients taking hydroxychloroquine, therefore it is advised that the dosage is lowered in patients with liver disease¹.

1. Chew CY, Mar A, Nikpour M, Saracino AM. Hydroxychloroquine in dermatology: new perspectives on an old drug. Australasian Journal of Dermatology. 2019; 61(2).
2. Tracy J.W. LW. Drugs used in the chemotherapy of protozoal infection: malaria. In: Hardman J.G., Limbird L.E., Molinoff P.B., editors. Goodman and Gilman’s the pharmacologic basis of Therapeutics. Vol 10. New York: McGraw-Hill. 2001. pp. 1059–1095.
3. Della Porta A, Bornstein K, Coye A, Montrief T, Long B, Parris MA. Acute chloroquine and hydroxychloroquine toxicity: A review for emergency clinicians. The American journal of emergency medicine. 2020; 38(10): 2209–2217.
4. CHM van Jaarsveld, ZN Jahangier, JWG Jacobs, AAM Blaauw, GA van Albada‐Kuipers, EJ ter Borg, HLM Brus, Y Schenk, MJ van der Veen, JWJ Bijlsma.Toxicity of anti‐rheumatic drugs in a randomized clinical trial of early rheumatoid arthritis. Rheumatology. 2000; 39(12): 1374–1382.