Check-up gastric symptoms as a side effect of medication

For some days now, I’ve had severe gastroenteritis-like symptoms. As well as vomiting and diarrhoea, I also had a rapid heart rate, dizziness and extreme fatigue. Is this typical?

In gastroenteritis, the type and severity of symptoms experienced depend on the type and quantity of microorganism or toxin ingested. Symptoms often begin suddenly with a loss of appetite, nausea or vomiting. Rumbling of the intestine and abdominal cramping may occur. Diarrhoea is the most common symptom and may be accompanied by visible blood and mucus. Sections of the intestine may be painfully distended with gas. Fever, aching muscles and extreme exhaustion may also be experienced. Severe vomiting and diarrhoea can lead to dehydration.

Symptoms of dehydration include weakness, decreased frequency of urination, dry mouth, and, in infants, lack of tears when crying. Excessive vomiting or diarrhoea can result in hypokalaemia – a low level of potassium in the blood. Low blood pressure and a rapid heart rate can also develop.

Low levels of sodium in the blood (hyponatraemia) also may develop, particularly if the person replaces lost fluids by drinking fluids that contain little or no salt, such as water and tea. Water and electrolyte imbalances are potentially serious, especially in the very young, the old, and people with chronic diseases. Shock and kidney failure can occur in severe cases.

A stool sample sent for examination showed no infection, so now my doctor thinks it may be a side effect of an antibiotic I was prescribed for a chest infection.

Nausea, vomiting and diarrhoea are common side effects of many drugs. These can include antacids containing magnesium, antibiotics, chemotherapy drugs and radiation therapy. Some medication for the treatment for gout and digoxin – a drug used for heart failure or certain irregular heart rhythms – may also precipitate a gastric problems. Other medications used in the treatment of internal parasitic worms, may cause gastrointestinal side effects. Laxative abuse can cause vomiting, diarrhoea, electrolyte loss, and other disturbances. Antibiotics may cause diarrhoea.

Recognising that a drug is causing gastroenteritis can be difficult. In mild cases, a doctor can have a person stop taking the drug and later start taking it again. If the symptoms subside when the person stops taking the drug and resume when the person starts taking it again, then the drug may be the cause of the gastrointestinal symptoms. In severe cases of gastroenteritis, a doctor may instruct the person to stop taking the drug permanently.