Drug Interaction:
Not indicated
Indication:
Hyperetension Antiadrenergic Agents- Centrally acting includes- Methyl Dopa, Clonidine, Guannfacine Hcl, Guanabenz Acetate,
Adverse Reaction:
Dry mouth, somnolence, asthenia, dizziness, headache, impotence, constipation, fatigue. Abdominal pain, diarrhea, dyspepsia, dysphagia, nausea, constipation, amnesia, confusion, depression, insomnia, decreased libido, parasthesias, vertigo, agitation, anxiety, malaise, nervousness, tremor.
Contra-Indications:
Hypersensitivity to guanfacine
Special precautions:
Special risk patients- severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease or chronic or hepatic failure.
Sedation- dose related. Abrupt cessation of therapy may be associated with increase in plasma and urinary catecholamines, symptoms of nervousness and anxiety.
Dosages/ Overdosage Etc:
Indications:
Hypertension
Dosage:
Recommended dose alone or with other antihypertensives is 1mg/day given at bed time to minimise daytime somnolence.
Patient Information:
GUANFACINE - ANTIHYPERTNSIVE
1. May produce drowsiness or dizziness; observe caution while driving, operating dangerous machinery or performing other tasks requiring alertness, coordination or physical dexterity.
2. Warn patients that tolerance for alcohol and other CNS depressants may be diminished.
3. Advise patients not to discontinue therapy abruptly.
4. Medication should be taken at bed time.
5. Allergy- Tell your doctor if you had any unusual reations to the medicine, or food substances, preservatives, dyestuffs.
6. Pregnancy- Not studied inpregnant women. However not shown to cause birth defects or oher problems in rats or rabbits given many times the human dose, except ( given at 200 times the human dose) an increase in deaths of animal fetus noticed.
7. Breast feeding- Not known whether guanfacine passes into breast milk. However medicines reported to cause problems in nursing babies
8. Children- Studies done only on adult patients. No specific information comparing use in children
9. Older adults- Dizziness, drowsiness, faitnes may be more likely to occur inthe elderly who are more sensitive
10. Other medicines- Tell your doctor if you are taking other prescription medicines or OTC products.
11. Other medical problems- Tell your doctor if you are having other medical problems especially- Heart disease or Heart attack or stroke - lowering of blood pressure may make problems resulting from these conditions Liver disease - effects may be decreased because of slower removal of guanafacine from the body Mental depresson- guanfacine may cause mental depression
12. Dosing- Follow doctors instructions
13. Missed dose- If you miss a dose of this medicine take it as soon as possible. However if it is almost time for your next dose go back to your regular dosing schedule. Do not double doses.
14. Storage- Keep the medicines out of reach of children Store the medicines away heat and direct light Do not store tablets or capsules in the bath room, in damp places near the kitchen sink Heat and dampness will cause the medicines to break down
Pharmacology/ Pharmacokinetics:
Antiadrenergic Agents- Centrally acting includes- Methyl Dopa, Clonidine, Guannfacine Hcl, Guanabenz Acetate,
Pharmacology:
Guanfacine is a centrally acting oral antihypertensive with alpha adreno-receptor agonist properties. Its principal mechanism of action appears to be stimulation of central alpa adrenergic receptors. Guanfacine reduces sympathetic nerve impulses from the vasomotor center to the heart and blood vessels, resulting in a decrease in peripheral vascular resistence and reduction in heart rate.
Pharmacokinetics:
Peak plasma concentrations occur from 1 to 4 hours with an average of 2.6 hours after single oral doses or at steady state. The drug is approximately 70% bound to plasma proteins, independent of drug concentration
Interaction with Food:
Not available
Pregnancy and lactation:
Pregnancy:
Use during pregnancy only if clearly needed.
Lactation:
Use caution when administering to a nursing mother.