when combined with alcohol or other depressant drugs the depressant effect of antihistamines can be much

Combining alcohol and other depressants and drugs can cause depression more then it takes it away

Increased blood pressure

Rapid heartbeat

Heartburn

Risk of ulcers

Sleepiness

Passing out or blackouts

Liver damage

Reduced blood-clotting ability

Memory lapses

Poor judgment

Slow reflexes, which can lead to harmful accidents

Distorted vision

Increased risk of some cancers