- Anticholinergic Medications are most common cause
- Psychiatric medications
- Upper Respiratory Medications
- Beta Blockers (e.g. Atenolol)
- Alpha Adrenergic Antagonist (e.g. Prazosin)
- Central Adrenergic Agonists (e.g. Clonidine)
- Diuretics
- Miscellaneous medications and drugs
- Muscle relaxants and antispasmodics
- Opioids
- Cannabinoids
- Protease Inhibitors
- Antiparkinsonian agents
- Proton Pump Inhibitors (e.g. Omeprazole)