Heart failure with reduced ejection fraction (off-label use):
Note: Alternative therapy for patients with persistent NYHA class III or IV heart failure with reduced ejection fraction (HFrEF) who cannot tolerate an angiotensin II receptor-neprilysin inhibitor, angiotensin-converting enzyme inhibitor, or angiotensin II receptor blocker or additional therapy in patients who have residual hypertension despite an optimal medical regimen for HFrEF (Ref).
Oral: Initial: 25 mg 3 times daily in combination with isosorbide dinitrate; titrate dose as tolerated every ≥1 to 2 weeks; target dose: 75 or 100 mg 3 times daily (Ref).
Hypertension, chronic (alternative agent):
Note: Not recommended for initial management but may be considered as additional therapy for resistant hypertension in patients who do not respond adequately to combination therapy with preferred agents. Consider combining with a beta-blocker and/or diuretic because hydralazine is associated with reflex tachycardia and fluid retention (Ref). For severe asymptomatic hypertension, may consider short-term use for BP lowering (eg, over hours) if there is concern that severe BP elevation will precipitate an acute cardiovascular event, such as in patients with known aortic or intracranial aneurysms. Some experts recommend captopril or clonidine, and hydralazine is considered an alternative agent in this situation (Ref).
Oral: Initial: 10 mg 4 times daily for 2 to 4 days, then 25 mg 4 times daily for the remainder of the week followed by titration based on response to 50 mg 4 times daily (Ref); usual dosage range: 100 to 200 mg/day in divided doses (Ref). Maximum dose: 300 mg/day in divided doses (manufacturer's labeling); however, doses >200 mg/day are generally avoided due to increased risk of lupus-like reaction (Ref). Patients with severe asymptomatic hypertension and no signs of acute end organ damage should be evaluated for medication adjustment within 1 week (Ref).
Hypertensive emergency (alternative agent):
Note: For severe elevation in blood pressure associated with new or worsening target-organ damage. Hydralazine is generally not recommended due to unpredictable and prolonged antihypertensive effects (Ref):
IM, IV: 10 to 20 mg every 4 to 6 hours as needed; may increase dose to a maximum of 40 mg/dose if necessary; some experts recommend a maximum of 20 mg/dose. Consider combining with a beta-blocker since hydralazine is associated with reflex tachycardia (Ref).
Hypertensive emergency in pregnancy or postpartum (including acute-onset severe hypertension in preeclampsia/eclampsia) (off-label use):
Note: For acute-onset, severe, persistent hypertension (eg, systolic BP ≥160 mm Hg or diastolic BP ≥110 mm Hg) (Ref).
IV: Initial: 5 or 10 mg; repeat with 5 to 10 mg doses every 20 to 40 minutes if BP continues to exceed thresholds (Ref). If systolic BP or diastolic BP remains above threshold after a total cumulative dose of 20 to 30 mg or if heart rate exceeds 100 beats per minute, another agent should be used (Ref).
Perioperative hypertension (alternative agent):
Note: For patients with chronic hypertension prior to surgery, restart oral therapies as soon as appropriate once hemodynamically stable. The antihypertensive effects of hydralazine are less predictable than other parenteral antihypertensives and can cause reflex tachycardia. Some experts suggest doses in the low end of the dosing range (Ref).
IV: 5 to 20 mg every 4 to 6 hours as needed (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Note: There are no dosage adjustments provided in the manufacturer's labeling. Limited data suggest concentrations of hydralazine and/or its metabolites are increased in patients with CrCl <50 mL/minute; however, results vary and there is no evidence of increased adverse effects (Ref).
Altered kidney function (Aronoff 2007; expert opinion derived from Levin 2010):
GFR ≥10 mL/minute: IM, IV, Oral: No dosage adjustment necessary.
GFR <10 mL/minute:
IM, IV: No dosage adjustment necessary when used short term; use with caution (Ref).
Oral: Administer usual dose every 8 to 12 hours (Ref).
Hemodialysis, intermittent (thrice weekly): Unlikely to be significantly dialyzed (Ref).
IM, IV: No dosage adjustment necessary when used short term; use with caution (Ref).
Oral: Administer usual dose every 8 to 12 hours (Ref). Avoid administering predialysis in patients who are prone to intra-dialytic hypotension (Ref).
Peritoneal dialysis: Unlikely to be significantly dialyzed (Ref).
IM, IV: No dosage adjustment necessary when used short term; use with caution (Ref).
Oral: Administer usual dose every 8 to 12 hours (Ref).
There are no dosage adjustments provided in the manufacturer's labeling; however, hydralazine undergoes extensive hepatic metabolism.
Refer to adult dosing.
(For additional information see "Hydralazine: Pediatric drug information")
Note: Individualize dose; titrate to patient response.
Heart failure, afterload reduction: Limited data available (Ref): Note: May cause reflex tachycardia; use in combination with beta-blocker therapy has been suggested (Ref).
IV:
Infants: 0.1 to 0.5 mg/kg/dose every 6 to 8 hours; maximum dose: 2 mg/kg/dose.
Children and Adolescents: 0.15 to 0.2 mg/kg/dose every 4 to 6 hours; maximum dose: 20 mg/dose.
Oral: Infants, Children, and Adolescents: 0.75 to 3 mg/kg/day divided every 6 to 12 hours; maximum daily dose: 7 mg/kg/day or 200 mg/day, whichever is less.
Hypertension, chronic: Children and Adolescents: Oral: Initial: 0.75 mg/kg/day in 2 to 4 divided doses; maximum initial adult dose: 10 mg/dose; may increase gradually over 3 to 4 weeks; maximum daily dose: 7.5 mg/kg/day not to exceed 200 mg/day (Ref).
Hypertension, acute severe : Note: Oral therapy should be used in patients with less severe symptoms; IV and IM therapy should be reserved for use in patients with life-threatening symptoms (Ref): Infants, Children, and Adolescents:
Oral: 0.25 mg/kg/dose every 6 to 8 hours as needed; maximum dose: 25 mg/dose (Ref).
IM, IV: Initial: 0.1 to 0.2 mg/kg/dose every 4 to 6 hours, titrate as needed; usual dosage range: 0.2 to 0.6 mg/kg/dose every 4 to 6 hours; maximum dose: 20 mg/dose (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Infants, Children, and Adolescents: There are no dosage adjustments provided in the manufacturer's labeling; however, the following adjustments have been recommended (Ref). Note: Renally adjusted dose recommendations are based on doses: Oral: 0.75 to 1 mg/kg/day divided every 6 to 12 hours; maximum daily dose: 200 mg/day; IV: 0.1 to 0.2 mg/kg/dose every 6 hours; maximum dose: 20 mg/dose.
GFR >50 mL/minute/1.73 m2: No adjustment necessary.
GFR 10 to 50 mL/minute/1.73 m2: Administer every 8 hours.
GFR <10 mL/minute/1.73 m2: Administer every 12 to 24 hours.
Intermittent hemodialysis: Administer every 12 to 24 hours.
Peritoneal dialysis (PD): Administer every 12 to 24 hours.
Continuous renal replacement therapy (CRRT): Administer every 8 hours.
There are no dosage adjustments provided in the manufacturer's labeling; however, hydralazine undergoes extensive hepatic metabolism.
Hydralazine-induced lupus-like syndrome (HILS) has occurred in up to 10% of patients on doses ≥200 mg for ≥3 months (Ref) and is reversible upon discontinuation. HILS commonly results in nonadherence or discontinuation and may lead to multi-organ involvement (pericarditis, hepatosplenomegaly); severe malaise/myalgias; acute joint pain and swelling; blood dyscrasias (leukopenia, thrombocytopenia); and positive serologies (antinuclear antibodies, antihistone antibodies, elevated erythrocyte sedimentation rate) (Ref).
Mechanism: Exact mechanism is unknown; may occur via IL-10 suppression at higher doses of hydralazine (Ref).
Onset: Delayed; onset reported after at least 3 months of therapy. However, this may vary based on dosing regimen (Ref). Duration of therapy in case reports varies from 1 to 24 months (Ref).
Risk factors:
• Females (Ref)
• White race (Ref)
• Slow hepatic acetylation (Ref)
• Doses ≥200 mg per day (Ref)
• Cumulative dose >100 g (Ref)
• Treatment for at least 3 months (Ref)
• Human leukocyte antigen DR4 genotype (Ref)
• Family history of autoimmune disease (Ref)
• History of thyroid disease (Ref)
• Null gene for C4 (Ref)
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
Frequency not defined:
Cardiovascular: Acute myocardial infarction, angina pectoris, edema (Cohn 2011), flushing, hypotension, myocardial stimulation, palpitations, paradoxical response to antihypertensive, tachycardia (Cohn 2011; Kandler 2011; Weingarten 2018)
Dermatologic: Pruritus, skin rash (including eczema) (Thestrup-Pederson 1987), urticaria (Thestrup-Pederson 1987)
Gastrointestinal: Anorexia (Paykel 1982), constipation, diarrhea (Paykel 1982), nausea (Paykel 1982), paralytic ileus, vomiting (Paykel 1982)
Genitourinary: Difficulty in micturition
Hematologic & oncologic: Agranulocytosis (Andrès 2017), eosinophilia, leukopenia, lymphadenopathy, purpuric disease, splenomegaly
Hepatic: Hepatitis (Amjad 2018)
Nervous system: Chills, dizziness, headache (Cohn 2011; Paykel 1982), peripheral neuropathy (Raskin 1965; Tsujimoto 1980), psychotic reaction (including anxiety, depression, disorientation, euphoria, hypomania, nervousness) (Paykel 1982)
Neuromuscular & skeletal: Arthralgia, muscle cramps, tremor
Ophthalmic: Conjunctivitis, lacrimation
Respiratory: Dyspnea, nasal congestion
Miscellaneous: Fever (Paykel 1982)
Postmarketing:
Cardiovascular: Vasculitis (Pendergraft 2014; Suneja 2014; Zuckerman 2018)
Dermatologic: Toxic epidermal necrolysis (Chan 2014)
Hematologic & oncologic: Hemolytic anemia (Kandler 2011)
Hepatic: Hepatotoxicity (Harati 2016; Sharma 2018)
Nervous system: Fatigue (Paykel 1982), malaise (Paykel 1982)
Neuromuscular & skeletal: Lupus-like syndrome (common: ≥10% in doses ≥200 mg for ≥3 months [Iyer 2017]; multi-organ involvement [eg, pericarditis, hepatosplenomegaly], severe malaise/myalgias, acute joint pain and swelling, blood dyscrasias [eg, leukopenia, thrombocytopenia], positive serologies [eg, antinuclear antibodies, antihistone antibodies, elevated erythrocyte sedimentation rate] [Handler 2012], and lupus erythematous-like rash [Thestrup-Pederson 1987])
Renal: Glomerulonephritis (Bjorck 1985; Suneja 2014)
Hypersensitivity to hydralazine or any component of the formulation; coronary artery disease; mitral valve rheumatic heart disease
Canadian labeling: Additional contraindications (not in US labeling): Idiopathic systemic lupus erythematosus and related diseases; severe tachycardia and heart failure (HF) with high cardiac output (eg, in thyrotoxicosis); myocardial insufficiency due to mechanical obstruction (eg, aortic or mitral stenosis, constrictive pericarditis); isolated right ventricular HF due to pulmonary hypertension; acute dissecting aneurysm of the aorta; porphyria (injection only)
Disease-related concerns:
• Cardiovascular disease: Use is contraindicated in patients with coronary artery disease (CAD). Use with caution in patients with cerebral vascular accidents and suspected CAD; myocardial stimulation produced by hydralazine can cause anginal attacks and electrocardiogram (ECG) changes of myocardial ischemia; has been implicated in the production of myocardial infarction. According to the American Heart Association/American College of Cardiology/American Society of Hypertension 2015 scientific statement for the treatment of hypertension in patients with CAD, hydralazine (without a concomitant nitrate [eg, isosorbide dinitrate]) should be avoided for the treatment of hypertension in patients with heart failure (with reduced ejection fraction) of ischemic origin (AHA/ACC/ASH [Rosendorff 2015]).
• Kidney impairment: Use with caution in patients with advanced kidney impairment; dosage adjustment recommended.
• Mitral valvular disease: Use with caution in patients with mitral valvular disease; may increase pulmonary artery pressure in these patients. Use is contraindicated in patients with mitral valve rheumatic heart disease.
Dosage form specific issues:
• Propylene glycol: Some dosage forms may contain propylene glycol; large amounts are potentially toxic and have been associated with hyperosmolality, lactic acidosis, seizures, and respiratory depression; use caution (AAP 1997; Zar 2007).
• Tartrazine sensitivity: May contain tartrazine, which may cause allergic-type reactions (including bronchial asthma) in certain susceptible individuals. Although the overall incidence of tartrazine sensitivity in the general population is low, it is frequently seen in patients who are also hypersensitive to aspirin.
Some dosage forms may contain propylene glycol; in neonates, large amounts of propylene glycol delivered orally, intravenously (eg, >3,000 mg/day), or topically have been associated with potentially fatal toxicities which can include metabolic acidosis, seizures, renal failure, and CNS depression; toxicities have also been reported in children and adults including hyperosmolality, lactic acidosis, seizures, and respiratory depression; use caution (AAP 1997; Shehab 2009).
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Injection, as hydrochloride:
Generic: 20 mg/mL (1 mL)
Tablet, Oral, as hydrochloride:
Generic: 10 mg, 25 mg, 50 mg, 100 mg
Yes
Solution (hydrALAZINE HCl Injection)
20 mg/mL (per mL): $4.20 - $18.00
Tablets (hydrALAZINE HCl Oral)
10 mg (per each): $0.12 - $0.41
25 mg (per each): $0.07 - $0.51
50 mg (per each): $0.08 - $0.56
100 mg (per each): $0.09 - $1.01
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Injection, as hydrochloride:
Apresoline: 20 mg/mL (1 mL)
Generic: 20 mg/mL (1 mL)
Tablet, Oral, as hydrochloride:
Generic: 10 mg, 25 mg, 50 mg
Oral: Administer without regard to meals. However, food enhances bioavailability; administer consistently with regard to meals.
Injection: Response may be delayed and unpredictable in some patients; titrate cautiously to response.
IM: Administer undiluted as IM injection.
IV: Administer undiluted as slow IV push.
Oral: May administer without regard to meals. However, food enhances bioavailability; administer consistently with regard to meals.
Parenteral:
IM: Administer undiluted as IM injection.
IV: Administer undiluted (20 mg/mL) as slow IV push over 1 to 2 minutes (Ref) maximum rate: 5 mg/minute (Ref).
Hypertension: Management of moderate to severe hypertension. Note: Not recommended for the initial treatment of hypertension (ACC/AHA [Whelton 2018]).
Heart failure with reduced ejection fraction; Hypertensive emergency in pregnancy or postpartum (including acute-onset severe hypertension in preeclampsia/eclampsia)
HydrALAZINE may be confused with hydroCHLOROthiazide, hydrOXYzine
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the Lexicomp drug interactions program by clicking on the “Launch drug interactions program” link above.
Alfuzosin: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Amifostine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Amifostine. Management: When used at chemotherapy doses, hold blood pressure lowering medications for 24 hours before amifostine administration. If blood pressure lowering therapy cannot be held, do not administer amifostine. Use caution with radiotherapy doses of amifostine. Risk D: Consider therapy modification
Amphetamines: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Risk C: Monitor therapy
Arginine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Barbiturates: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Benperidol: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Brigatinib: May diminish the antihypertensive effect of Antihypertensive Agents. Brigatinib may enhance the bradycardic effect of Antihypertensive Agents. Risk C: Monitor therapy
Brimonidine (Topical): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Bromperidol: May diminish the hypotensive effect of Blood Pressure Lowering Agents. Blood Pressure Lowering Agents may enhance the hypotensive effect of Bromperidol. Risk X: Avoid combination
Dapoxetine: May enhance the orthostatic hypotensive effect of HydrALAZINE. Risk C: Monitor therapy
Dexmethylphenidate: May diminish the therapeutic effect of Antihypertensive Agents. Risk C: Monitor therapy
Diazoxide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
DULoxetine: Blood Pressure Lowering Agents may enhance the hypotensive effect of DULoxetine. Risk C: Monitor therapy
Flunarizine: May enhance the therapeutic effect of Antihypertensive Agents. Risk C: Monitor therapy
Herbal Products with Blood Pressure Increasing Effects: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Herbal Products with Blood Pressure Lowering Effects: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents. Risk C: Monitor therapy
Indoramin: May enhance the hypotensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Levodopa-Foslevodopa: Blood Pressure Lowering Agents may enhance the hypotensive effect of Levodopa-Foslevodopa. Risk C: Monitor therapy
Loop Diuretics: May enhance the hypotensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Lormetazepam: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Methylphenidate: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy
Molsidomine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Naftopidil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Nicergoline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Nicorandil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Nitroprusside: Blood Pressure Lowering Agents may enhance the hypotensive effect of Nitroprusside. Risk C: Monitor therapy
Nonsteroidal Anti-Inflammatory Agents: May diminish the antihypertensive effect of HydrALAZINE. Risk C: Monitor therapy
Obinutuzumab: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Risk D: Consider therapy modification
Pentoxifylline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Pholcodine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Pholcodine. Risk C: Monitor therapy
Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Prazosin: Antihypertensive Agents may enhance the hypotensive effect of Prazosin. Risk C: Monitor therapy
Prostacyclin Analogues: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Quinagolide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Silodosin: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy
Terazosin: Antihypertensive Agents may enhance the hypotensive effect of Terazosin. Risk C: Monitor therapy
Urapidil: Antihypertensive Agents may enhance the hypotensive effect of Urapidil. Risk C: Monitor therapy
Food enhances bioavailability of hydralazine. Management: Administer without regard to food, but keep consistent.
Medications considered acceptable for the treatment of chronic hypertension during pregnancy may generally be used in patients trying to conceive. Patients planning to become pregnant may continue taking oral hydralazine for the treatment of chronic hypertension when effective (ACC/AHA [Whelton 2018]; NICE 2019; SOGC [Magee 2022]).
Hydralazine crosses the placenta (Lamont 1986; Liedholm 1982).
High and frequent doses of IV hydralazine are associated with adverse events, such as maternal hypotension and fetal tachycardia, compared to other agents (ACOG 2019; ESC [Cífková 2020]; SOGC [Magee 2022]).
Chronic maternal hypertension is associated with adverse events in the fetus/infant. Chronic maternal hypertension may increase the risk of birth defects, low birth weight, premature delivery, stillbirth, and neonatal death. Actual fetal/neonatal risks may be related to the duration and severity of maternal hypertension. Untreated chronic hypertension may also increase the risks of adverse maternal outcomes, including gestational diabetes, preeclampsia, delivery complications, stroke, and myocardial infarction (ACOG 2019).
Due to pregnancy-induced physiologic changes and maternal acetylator status (NAT2 genotype), some pharmacokinetic properties of oral hydralazine may be altered. Larger studies are needed to evaluate if or how these changes influence safety or efficacy during pregnancy (Han 2019).
Patients with preexisting hypertension may continue their medication during pregnancy unless contraindications exist (ESC [Regitz-Zagrosek 2018]). When treatment of hypertension is initiated during pregnancy, agents other than oral hydralazine may be preferred (ACOG 2019; ESC [Regitz-Zagrosek 2018]); oral hydralazine is considered an alternative option due to possible side effects (SOGC [Magee 2022]).
IV hydralazine is recommended for use in the management of acute onset, severe hypertension (systolic BP ≥160 mm Hg or diastolic BP ≥110 mm Hg) with preeclampsia or eclampsia in pregnant and postpartum patients (ACOG 2020; ESC [Cífková 2020]; SOGC [Magee 2022]).
Hydralazine is present in breast milk.
Data related to the presence of hydralazine in breast milk are available from a patient receiving oral hydralazine 50 mg 3 times a day, initiated prior to delivery. Hydralazine and metabolites were present in breast milk sampled 30 minutes after a midday dose at 8 weeks postpartum (Liedholm 1982). In a study of 4 breastfeeding women, breast milk concentrations of hydralazine were approximately one-half of maternal serum concentrations. Hydralazine was detected in the serum of their breastfeeding infants at a concentration 10 times smaller than concentrations found in a hypertensive infant being treated therapeutically with hydralazine (Lamont 1986).
The manufacturer recommends that caution be used if administered to patients who are breastfeeding. Hydralazine is considered compatible with breastfeeding; however, sufficient data are not available following long-term use (WHO 2002).
Blood pressure; heart rate; complete blood cell count (CBC); antinuclear antibody (ANA) titer.
Direct vasodilation of arterioles (with little effect on veins) with decreased systemic resistance. Although exact mechanism unknown, arterial vasodilation may occur via inhibition of calcium release from the sarcoplasmic reticulum and inhibition of myosin phosphorylation in arterial smooth muscle cells (McComb 2016).
Onset of action: IV: 10 to 80 minutes
Duration: IM, IV: Up to 12 hours (Marik 2007); Note: Duration may vary depending on acetylator status of patient. Hypotension due to hydralazine may last longer even though the circulating half-life is much shorter (Marik 2007; O’Malley 1975).
Absorption: Oral: Rapidly absorbed
Protein binding: 87%
Metabolism: Hepatically acetylated; extensive first-pass effect (oral)
Bioavailability: ~22% to 69% depending on acetylator status (increased in slow acetylators and decreased in rapid acetylators) (Ludden1982); increased with food
Half-life elimination: 3 to 7 hours
Time to peak, plasma: Oral: 1 to 2 hours
Excretion: Urine (as metabolites)
Slow acetylators: Patients will generally have higher plasma levels of hydralazine and require lower doses to maintain control of BP.
آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟