Histamine-1 receptor antagonist

Definition

Histamine-1 receptor antagonists are drugs that block the H1 receptors, preventing histamine from exerting its effects. They are primarily used to treat allergic reactions, but also have sedative properties useful in antipsychotic treatments.

5 Must Know Facts For Your Next Test

1. Histamine-1 receptor antagonists can cross the blood-brain barrier, causing sedation and drowsiness.
2. These drugs are often used as adjunct therapy in treating anxiety and insomnia associated with psychotic disorders.
3. Common side effects include dizziness, dry mouth, and urinary retention.
4. They can interact with other central nervous system depressants, enhancing sedative effects.
5. First-generation H1 antagonists are more likely to cause central nervous system side effects compared to second-generation H1 antagonists.

Review Questions

• What is the primary mechanism of action of histamine-1 receptor antagonists?
• List two common side effects of first-generation histamine-1 receptor antagonists.
• Why might a histamine-1 receptor antagonist be prescribed alongside an antipsychotic medication?

Related terms

Antihistamines:

Drugs that inhibit the action of histamine at the H1 or H2 receptors.

Sedatives: Substances that induce sedation by reducing irritability or excitement.

Blood-Brain Barrier:

A selective barrier that prevents certain substances from entering the brain from the bloodstream.