Pseudoephedrine: very rare risk of posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS)
Patients should be advised to be alert to the symptoms for PRES and RCVS, to stop the medication immediately and to seek urgent medical attention if these occur. Pseudoephedrine-containing medicines should be used for short-term, symptomatic use only and avoided in hypertension.
Source:
Medicines and Healthcare products Regulatory Agency
SPS commentary:
PRES and RCVS present with the following symptoms: sudden severe headache or thunderclap headache, sudden onset of nausea and vomiting, confusion, seizures and/or visual disturbances.