THERAPEUTICS

Brands

• Tenex, Intuniv

Generic?

• Yes

Class

• α2-adrenergic agonist

Commonly Prescribed for

(FDA approved in bold)

• Attention deficit hyperactivity disorder (ADHD)

• Hypertension

• Gilles de la Tourette syndrome (GTS)

• Tics

• Neuropathic pain

• Opioid detoxification

• Alcohol withdrawal

• Hypertensive “urgency”

• Post-traumatic stress disorder

How the Drug Works

• A centrally acting α2A-adrenergic agonist. Reduces sympathetic output from CNS, which decreases cardiac output, peripheral vascular resistance, and blood pressure

• Specifically targets α2A receptors in the brainstem vasomotor center, decreasing presynaptic calcium levels and the release of norepinephrine

How Long Until It Works

• ADHD: after 1 week

• Hypertension, withdrawal: less than 2 hours

• GTS: weeks to months

If It Works

• In neurological disorders, such as tics, continue to assess effect of the medication to see if it is still needed

If It Doesn't Work

• GTS/tics: neuroleptics are often effective, but their use should be reserved for patients with significant social isolation or embarrassment

Best Augmenting Combos for Partial Response or Treatment-Resistance

• In hypertension, combine with treatments less likely to cause orthostasis (ACE inhibitors, diuretics)

• Tics and GTS symptoms may change over time. Many patients improve with age. Behavioral and psychological therapies are useful and education and reassurance are all that is needed in mild cases

• Indentify and treat comorbid conditions such as ADHD or obsessive-compulsive disorder

Tests

• Monitor blood pressure and pulse

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• Related to α2A-adrenergic agonist effect – hypotension and sedation

Notable AEs

• Dry mouth, drowsiness, dizziness, constipation, weakness, headache, depression, paresthesia, dermatitis, impotence, and syncope

Life-Threatening or Dangerous AEs

• Hypotension, bradycardia, and syncope

• Rapid withdrawal can cause rebound hypertension with increased catecholamine levels

Weight Gain

• Unusual

Sedation

• Common

What to Do About AEs

• Lower the dose and take the highest dose in the evening. Many AEs (especially sedation) decrease with time