Dextromethorphan HBr: Rarely, nausea, GI discomfort, drowsiness, excitation & mental confusion. Phenylephrine HCI: Tremor, restlessness, anxiety, insomnia/sleeplessness, nervousness, increased BP, palpitation, arrhythmia, weakness, resp distress & pallor. Paracetamol: Skin rashes, hypersensitivity reactions, changes in number of WBC & platelet & minor stomach & intestinal disturbances. Dextromethorphan HBr & phenylephrine HCl: Dizziness.