Drug-induced parotitis is uncommon and can be a challenge to diagnose.


Potential mechanisms:

(1) anticholinergic effect (associated with dry mouth)

(2) direct toxic effect


Criteria for diagnosis:

(1) absence of parotitis before starting drug

(2) onset of parotitis (swelling, pain) after starting drug

(3) reversal of parotitis after discontinuation of drug

(4) exclusion of other causes

(5) recurrence on re-exposure (often not performed)


Drugs with good evidence of causing drug-induced parotitis:

(1) phenylbutazone or oxyphenbutazone

(2) antipsychotic drugs (clozapine, thioridazine)

(3) l-asparaginase


Other drugs have been implicated but not proven as causes:

(1) H2-receptor antagonists

(2) interferon-alpha

(3) doxycycline

(4) trimipramine

(5) nifedipine

(6) methyldopa

(7) nitrofurantoin

(8) nicardipine

(9) isoproterenol

(10) ritodrine


Differential diagnosis:

(1) lithiasis

(2) Sjogren’s syndrome or other autoimmune disorder

(3) infectious parotitis


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