suppressants

Suppressants are substances that reduce, inhibit, or prevent a biological process or response. They can be chemicals, drugs, or devices used in medicine, biology, and public health. Suppression can target physiological functions such as coughing, appetite, immune activity, or gastric acid production, among others. Suppressants differ from stimulants, which increase activity, and from suppressors used for mechanical or environmental control.

Cough suppressants, or antitussives, relieve coughing by acting on the cough reflex. Central agents depress the cough center in the medulla, while peripheral agents reduce cough receptor sensitivity. Common pharmaceutical examples include dextromethorphan and, in some countries, codeine-containing preparations. They are typically used for short periods in nonproductive or irritating coughs. Potential side effects include drowsiness, dizziness, and risk of misuse with opioids.

Immunosuppressants reduce immune system activity and are essential in organ transplantation and autoimmune disease management. They include calcineurin inhibitors (cyclosporine, tacrolimus), mTOR inhibitors (sirolimus), antimetabolites (azathioprine, mycophenolate mofetil), and corticosteroids. They work by limiting T cell activation or proliferation. They carry risks such as infection, metabolic changes, and drug interactions; treatment requires careful monitoring and often combination regimens.

Appetite suppressants (anorectics) aim to reduce caloric intake by affecting appetite regulation in the brain or by metabolic effects. Historically used for obesity, modern agents are prescribed under strict guidelines due to cardiovascular and psychiatric risks. Examples include phentermine and diethylpropion; newer non-stimulant options exist. Side effects vary but commonly include dry mouth, insomnia, elevated blood pressure, and potential dependence with stimulant forms.

Gastric acid suppressants reduce stomach acid production. They include H2 receptor antagonists (famotidine) and proton pump inhibitors (omeprazole). They are used for gastroesophageal reflux disease, ulcers, and related conditions. While effective for symptom relief and healing, long-term use can affect nutrient absorption and may lead to rebound acid production after stopping.