- ACRONYMS AND DEFINITIONS
- HCTZ - Hydrochlorothiazide
Clonidine (Catapres®)
Dosage forms
Tablet
- 0.1 mg
- 0.2 mg
- 0.3 mg
Dosing
Hypertension
- Starting: 0.1 mg twice a day
- Maintenance: 0.1 - 0.3 mg twice a day
- Max: 2.4 mg/day (doses this high are not typical)
- Increase dose by 0.1 mg a day at weekly intervals
- May take without regard to food
Kidney disease
- 40 - 60% of clonidine is excreted in the urine as unchanged drug. Kidney disease increases exposure and caution should be used.
Liver disease
- About 50% of clonidine is metabolized by the liver. Liver disease increases exposure and caution should be used.
Generic / Price
- YES/$Clonidine (Catapres-TTS®)
Dosage forms
Patch
- TTS-1 delivers 0.1 mg per day for 7 days
- TTS-2 delivers 0.2 mg per day for 7 days
- TTS-3 delivers 0.3 mg per day for 7 days
Dosing
Hypertension
- Starting: One TTS-1 patch for 7 days
- Maintenance: Increase up to two TTS-3 patches as needed
- Max: Two TTS-3 patches (0.6 mg/day)
- Increase dose at 1 - 2 week intervals
Kidney disease
- 40 - 60% of clonidine is excreted in the urine as unchanged drug. Kidney disease increases exposure and caution should be used.
Liver disease
- About 50% of clonidine is metabolized by the liver. Liver disease increases exposure and caution should be used.
Generic / Price
- YES/$-$$Other
- One patch is good for 7 days
- Apply patch to hairless, intact skin of upper outer arm or chest
- When initiating patch, it may take 2 - 3 days for blood pressure effect to be realized. Patients may need to continue current doses of BP meds for the first 2 - 3 days when applicable.
- Apply each new patch to a different area of skin
- Remove old patch before applying new patch
- Normal exposure to water should not affect patch
- Do not wear during MRI or electrical cardioversion
Methyldopa (Aldomet®)
Dosage forms
Tablet
- 250 mg
- 500 mg
Dosing
Hypertension
- Starting: 250 mg two to three times a day
- Maintenance: 500 - 2000 mg/day
- Max: 3000 mg/day
- Give in two to four divided doses
- Increase dose at intervals of ≥ 2 days
- May take without regard to food
Kidney disease
- Methyldopa is excreted extensively in the urine. Kidney disease increases exposure and caution should be used.
Liver disease
- Methyldopa has been associated with hepatotoxicity and is not recommended in active liver disease. Use caution in chronic disease.
Generic / Price
- YES/$Other
- Tolerance may develop in some patients after 2 - 3 months of therapy
Aldoril® (methyldopa + HCTZ)
Dosage forms
Tablet
- Methyldopa - HCTZ
- 250 mg - 15 mg
- 250 mg - 25 mg
Dosing
Hypertension
- Starting: 250/15 mg two to three times a day OR 250/25 mg twice a day
- Max: Methyldopa - 3000 mg/day; HCTZ 50 mg/day
- May take without regard to food
Generic / Price
- YES/$- Kidney disease
- Clonidine
- 40 - 60% of clonidine is excreted in the urine as unchanged drug. Kidney disease increases exposure and caution should be used. [1]
- Methyldopa
- Methyldopa is excreted extensively in the urine. Kidney disease increases exposure and caution should be used. [2]
- Liver disease
- Clonidine
- About 50% of clonidine is metabolized by the liver. Liver disease increases exposure and caution should be used. [1]
- Methyldopa
- Methyldopa has been associated with hepatotoxicity and is not recommended in active liver disease. Use caution in chronic disease. [2]
- DRUG INTERACTIONS
- NOTE: The drug interactions presented here are NOT all-inclusive. Other interactions may exist. Drug interaction checkers provide the most efficient and practical way to check for interactions among multiple medications. A free interaction checker is available from Drugs.com (see Drugs.com interactions checker).
- Clonidine and Methyldopa
- Sedating drugs (alcohol, benzodiazepines, etc.) - drugs that cause sedation may worsen the sedative effects of clonidine and methyldopa
- Tizanidine (Zanaflex®) - tizanidine is an alpha-2 agonist used as a muscle relaxer. It should not be combined with clonidine or methyldopa because it may increase the risk of adverse events.
- Medications that slow the heart rate - clonidine and methyldopa can slow the heart rate. When taken with other heart rate-slowing medications, the effect may be potentiated, and bradycardia can occur.
- Common drugs that slow the heart rate include:
- Amiodarone (Cordarone®)
- Beta blockers
- Calcium channel blockers (diltiazem and verapamil)
- Digoxin (Lanoxin®)
- Fingolimod (Gilenya®)
- Ivabradine (Corlanor®)
- Siponimod (Mayzent®)
- Clonidine
- Beta blockers - patients taking clonidine with beta blockers may experience severe rebound hypertension if they abruptly stop clonidine. To prevent this, it is recommended that the beta blocker be stopped several days before clonidine is withdrawn. Clonidine can then be tapered over 2 - 4 days.
- Tricyclic antidepressants (amitriptyline, desipramine, imipramine, etc.) - tricyclic antidepressants may decrease the effects of clonidine [1]
- Methyldopa
- Iron supplements (ferrous sulfate, ferrous gluconate) - iron supplements can reduce the absorption of methyldopa, even with a two-hour space between dosing. The ideal interval between iron and methyldopa administration has not been determined, so patients should take the drugs as far apart as possible. [2,3]
- Lithium - methyldopa may increase lithium exposure. Monitor lithium levels closely when combining. [2]
- MAO inhibitors (Selegiline, Eldepryl®, phenelzine, rasagiline, Azilect® etc) - methyldopa should not be taken with MAO inhibitors.
- Metabolism and clearance
- Clonidine (Catapres®)
- CYP2D6 - substrate [4]
- Methyldopa
- Not well-defined
- PRICE ($) INFO
Pricing legend
- $ = 0 - $50
- $$ = $51 - $100
- $$$ = $101 - $150
- $$$$ = > $150
- Pricing based on one month of therapy at standard dosing in an adult
- Pricing based on information from GoodRX.com®
- Pricing may vary by region and availability
- BIBLIOGRAPHY
- 1 - Clonidine PI
- 2 - Methyldopa PI
- 3 - PMID 2054263
- 4 - PMID 20570945