Carbocisteine is generally safe.
Immune system disorders: Anaphylactic reaction (rare, life-threatening allergic reaction).
Endocrine disorders: Transient hypothyroidism (temporary deficiency of thyroid hormone) in a patient with compromised thyroid function.
Metabolism and nutrition disorders: Mild hypoglycemia (mild lowering of blood sugar).
Psychiatric disorders: Insomnia (sleeplessness).
Nervous system disorders: Dizziness, headache, palpitations.
Cardiac disorders: Atrial fibrillation (abdominal heart rhythm).
Gastrointestinal disorders: Dryness of mouth, flatulence (gassiness), gastric hemorrhage (stomach bleeding), vomiting.
Skin and subcutaneous tissue disorders: Angioedema (deep swelling around the eyes and lips and sometimes of the hands and feet), urticaria (hives), rare cases of serious skin reactions (e.g., bullous dermatitis, Stevens-Johnson syndrome, erythema multiforme) which may include symptoms such as redness, rash, blisters and skin shedding.
The most commonly reported undesirable effects associated with doses of elemental Zinc greater than 30 mg.
Metabolism and nutrition disorders: Loss of appetite.
Psychiatric disorders: Drowsiness.
Nervous system disorders: Headache, metallic taste.
Gastrointestinal disorders: Abdominal pain/ cramps, diarrhea, dyspepsia, gastritis (inflammation of the stomach), gastrointestinal discomfort / irritation, nausea, vomiting.
For suspected adverse drug reaction, seek medical attention immediately.