U r taking the drug aminophylline
derivative), mixed in the cough syrup.
The causes of ur shivering could be 1. aminophylline excess in ur blood levels 2. Caffeine toxicity 3. and rarely alcohol withdrawal
(the syrup contains alcohol).
U need to measure the serum levels of aminophylline first. If it's excess, gradually reduce the dosage of ur cough syrup and switch over to inhaler medications.
For the shivering, u may need to take propranolol
. Dont take additional coffee or tea until u withdraw from the syrup. Consult ur doctor for using inhaler and propranolol