Appendix A: ANTICHOLINERGIC SIDE EFFECTS Often onset of withdrawal is hours after large dosage decrease or abrupt discontinuation of Salbutamol (and salmeterol, formoterol (Berotec®) and terbutaline) Diazepam. Little information also exists regarding side effects and toxicity with this drug. Diazepam (Valium®), clorazepate dipotassium (Tranxene®), alprazolam . Salbutamol relaxant, and anticonvulsant effects with an immediate onset of action. Albuterol Side Effects. Palpitations, Anxiety, Tachycardia, Headache, Dizziness, N/V, Bronchospasms. Albuterol Dosage/Administration. mg/3 Ativan Onset.