Several drugs are secreted in saliva. This process is largely determined by passive diffusion, meaning only unbound drugs in the blood plasma can transfer to saliva.
Examples of Drugs Found in Saliva:
- Caffeine: A common stimulant found in coffee, tea, and other beverages.
- Phenytoin: An anticonvulsant medication used to treat seizures.
- Theophylline: A bronchodilator often used to treat asthma and other respiratory conditions.
Other drugs may also be present in saliva, but their concentrations may vary based on individual factors and the drug's properties. The amount of a drug present in saliva can be relevant for drug monitoring and detection of drug abuse. It is important to note that the presence of a drug in saliva doesn't necessarily indicate a specific therapeutic effect, and its concentration might not always reflect blood levels.
While some medications can cause dry mouth (xerostomia) by affecting saliva production, this doesn't mean the medications themselves are secreted into the saliva. The references mention medications impacting salivary glands, but don't explicitly state those medications themselves are components of the saliva itself.
The concentration of a drug found in saliva can be influenced by various factors including:
- Drug properties: Lipid solubility and protein binding affinity affect the ease of passive diffusion into the saliva.
- Dosage and route of administration: Higher doses and intravenous administration generally lead to higher salivary concentrations.
- Individual metabolism and clearance rates: These affect the amount of drug in the plasma available for diffusion.
