Dosing & Uses
Dosage Forms & Strengths
Not for initial therapy
Usual dose: 25 mg/25 mg PO q12hr
Maximum: 100 mg/50 mg PO q12hr
Dosage strength determined by individual titration
Use caution in dosing/titrating patients with renal dysfunction
Cumulative effects of thiazides may develop with impaired renal function; dose adjustment may be necessary; azotemia may be precipitated
Dosage adjustment may be required in geriatrics
To minimize dose-independent side effects, begin combination therapy only after patient fails to achieve desired effect with monotherapy
<18 years: Safety/efficacy not established
Serious - Use Alternative
Significant - Monitor Closely
Frequency Not Defined
- Peripheral neuropathy
- Nasal congestion
- Hemolytic anemia
- AnorexiaEpigastric distress
- Orthostatic hypotension
- Erythema multiforme
- Stevens-Johnson syndrome
- Exfoliative dermatitis including toxic epidermal necrolysis
Black Box Warnings
Do not use fixed dose combination for intial treatment of hypertension
Hypertension requires gradual titration according to individual patient requirements
Reevaluate hypertension treatment as necessary
Hypersensitivity to either component or sulfonamides
Coronary artery disease
Dissecting aortic aneurysm
Mitral valve rheumatic heart disease
This fixed-combination drug is not indicated for initial therapy of hypertension; requires therapy titrated to the individual patient before fixed-combination drug therapy initiated
May induce SLE-type syndrome (usually at doses >200 mg/day); instruct patients to report joint/chest pain or fever; consider discontinuation if occurs
DM, fluid or electrolyte imbalance, hyperuricemia or gout, liver disease, renal disease
May aggravate digitalis toxicity
Sensitivity reactions may occur with or without history of allergy or asthma
CVA, severe renal impairment, volume depletion, preexisting hypotension, concurrency with other hypotensive agents
Discontinue slowly to avoid rapid rise in BP
Risk of male sexual dysfunction
Acute transient myopia and acute angle-closure glaucoma has been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is a sulfonamide)
Pregnancy & Lactation
Pregnancy Category: C
Lactation: enters breast milk; compatible
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Mechanism of Action
Hydralazine/hydrochlorothiazide is a fixed-combination tablet that combines a vasodilator, hydralazine and a thiazide diuretic, hydrochlorothiazide
Hydralazine, a direct vasodilator, dilates arterioles with little effect on veins; decreases systemic resistance
Hydrochlorothiazide, a thiazide diuretic, inhibits Na reabsorption in distal renal tubules resulting in increased excretion of Na+ and water, also K+ and H+ ions
- Onset: 20-30 min (PO); 5-20 min (IV)
- Half -life: 2-8 hr (normal renal function); 7-16 hr (end stage renal disease)
- Duration: Up to 8 hr (PO); 1-4 hr (IV)
- Excretion: Urine (14%)
- Protein binding (85-90%)
- Metabolism: Liver
- Half-Life: 6-15 hr
- Bioavailability: 70%
- Onset: 2 hr (diuresis); 4-6 hr (peak effect)
- Duration: 6-12 hr (diuresis); 1 wk (HTN)
- Vd: 3.6-7.8 L/kg
- Peak Plasma:1.5-2.5 hr
- Protein Bound: 68%
- Metabolism: Minimally metabolized
- Clearance: 335 mL/min
- Excretion: Urine 50-70%
- Dialyzable: No
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.
|1||This drug is available at the lowest co-pay. Most commonly, these are generic drugs.|
|2||This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.|
|3||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.|
|4||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|5||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|6||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|NC||NOT COVERED – Drugs that are not covered by the plan.|
Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.