Enasidenib Mesylate and Verapamil Hydrochloride

• Generic Name: enasidenib
• Dosage Forms: n.a.
• Other Brand Names: Idhifa, Idhifa

For the treatment of relapsed or refractory AML with IDH2 mutation (designated an orphan drug by FDA for this use).

FDA-approved diagnostic test (e.g., Abbott RealTime IDH2 assay) required to confirm the presence of IDH2 mutation prior to initiation of therapy.

• Generic Name: verapamil
• Dosage Forms: n.a.
• Other Brand Names: Calan, Isoptin SR, Verelan, Isoptin, Calan SR, Isoptin IV, Covera-HS, Verelan PM

IV management of supraventricular tachycardia (SVT), including rapid conversion to sinus rhythm of paroxysmal supraventricular tachycardias (PSVT) (e.g., those associated with Wolff-Parkinson-White or Lown-Ganong-Levine syndrome), and temporary control of rapid ventricular rate in atrial flutter or fibrillation.

Vagal maneuvers and/or IV adenosine are considered first-line interventions for acute treatment of SVT when clinically indicated; if such measures are ineffective or not feasible, a nondihydropyridine calcium-channel blocker such as verapamil may be used. Use only in hemodynamically stable patients who do not have impaired ventricular function.

Also has been used for treatment of other SVTs (e.g., atrial tachycardia, junctional tachycardia).

An oral treatment of choice to prevent recurrent PSVT.

Oral management (alone or in combination with a cardiac glycoside) to control ventricular rate at rest and during stress in patients with chronic atrial fibrillation and/or flutter.

Angina

Management of chronic stable angina, Prinzmetal variant angina, and unstable angina.

A drug of choice for the management of Prinzmetal variant angina (used alone or in combination with nitrates).

β-Blockers are recommended as the anti-ischemic drugs of choice in most patients with chronic stable angina; calcium-channel blockers may be substituted or added in patients who do not tolerate or respond adequately to β-blockers.

Experts recommend a nondihydropyridine calcium-channel blocker (e.g., diltiazem, verapamil) for the relief of ongoing or recurrent ischemia when β-blocker therapy is inadequate, not tolerated, or contraindicated in patients with unstable angina who do not have clinically important left ventricular dysfunction, increased risk of cardiogenic shock, or AV block.

Hypertension

Oral management of hypertension, alone or in combination with other classes of antihypertensive agents.

Calcium-channel blockers are recommended as one of several preferred agents for the initial management of hypertension according to current evidence-based hypertension guidelines; other preferred options include ACE inhibitors, angiotensin II receptor antagonists, and thiazide diuretics. While there may be individual differences with respect to recommendations for initial drug selection and use in specific patient populations, current evidence indicates that these antihypertensive drug classes all generally produce comparable effects on overall mortality and cardiovascular, cerebrovascular, and renal outcomes.

Individualize choice of therapy; consider patient characteristics (e.g., age, ethnicity/race, comorbidities, cardiovascular risk) as well as drug-related factors (e.g., ease of administration, availability, adverse effects, cost).

A 2017 ACC/AHA multidisciplinary hypertension guideline classifies BP in adults into 4 categories: normal, elevated, stage 1 hypertension, and stage 2 hypertension.

Source: Whelton PK, Carey RM, Aronow WS et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018;71:e13-115.

Individuals with SBP and DBP in 2 different categories (e.g., elevated SBP and normal DBP) should be designated as being in the higher BP category (i.e., elevated BP).

The goal of hypertension management and prevention is to achieve and maintain optimal control of BP. However, the BP thresholds used to define hypertension, the optimum BP threshold at which to initiate antihypertensive drug therapy, and the ideal target BP values remain controversial.

The 2017 ACC/AHA hypertension guideline generally recommends a target BP goal (i.e., BP to achieve with drug therapy and/or nonpharmacologic intervention) <130/80 mm Hg in all adults regardless of comorbidities or level of atherosclerotic cardiovascular disease (ASCVD) risk. In addition, an SBP goal of <130 mm Hg generally is recommended for noninstitutionalized ambulatory patients ≥65 years of age with an average SBP of ≥130 mm Hg. These BP goals are based upon clinical studies demonstrating continuing reduction of cardiovascular risk at progressively lower levels of SBP.

Previous hypertension guidelines generally have based target BP goals on age and comorbidities. Guidelines such as those issued by the JNC 8 expert panel generally have targeted a BP goal of <140/90 mm Hg regardless of cardiovascular risk, and have used higher BP thresholds and target BPs in elderly patients compared with those recommended by the 2017 ACC/AHA hypertension guideline.

Some clinicians continue to support previous target BPs recommended by JNC 8 due to concerns about the lack of generalizability of data from some clinical trials (e.g., SPRINT study) used to support the 2017 ACC/AHA hypertension guideline and potential harms (e.g., adverse drug effects, costs of therapy) versus benefits of BP lowering in patients at lower risk of cardiovascular disease.

Consider potential benefits of hypertension management and drug cost, adverse effects, and risks associated with the use of multiple antihypertensive drugs when deciding a patient's BP treatment goal.

For decisions regarding when to initiate drug therapy (BP threshold), the 2017 ACC/AHA hypertension guideline incorporates underlying cardiovascular risk factors. ASCVD risk assessment recommended by ACC/AHA for all adults with hypertension.

ACC/AHA currently recommend initiation of antihypertensive drug therapy in addition to lifestyle/behavioral modifications at an SBP ≥140 mm Hg or DBP ≥90 mm Hg in adults who have no history of cardiovascular disease (i.e., primary prevention) and a low ASCVD risk (10-year risk <10%).

For secondary prevention in adults with known cardiovascular disease or for primary prevention in those at higher risk for ASCVD (10-year risk ≥10%), ACC/AHA recommend initiation of antihypertensive drug therapy at an average SBP ≥130 mm Hg or an average DBP ≥80 mm Hg.

Adults with hypertension and diabetes mellitus, chronic kidney disease (CKD), or age ≥65 years of age are assumed to be at high risk for cardiovascular disease; ACC/AHA state that such patients should have antihypertensive drug therapy initiated at a BP ≥130/80 mm Hg. Individualize drug therapy in patients with hypertension and underlying cardiovascular or other risk factors.

In stage 1 hypertension, experts state that it is reasonable to initiate drug therapy using the stepped-care approach in which one drug is initiated and titrated and other drugs are added sequentially to achieve the target BP. Initiation of antihypertensive therapy with 2 first-line agents from different pharmacologic classes recommended in adults with stage 2 hypertension and average BP >20/10 mm Hg above BP goal.

Calcium-channel blockers may be preferred in hypertensive patients with certain coexisting conditions (e.g., ischemic heart disease) and in geriatric patients, including those with isolated systolic hypertension. Nondihydropyridine calcium-channel blockers (e.g., diltiazem, verapamil) may be beneficial in hypertensive patients with coexisting atrial fibrillation and a rapid ventricular rate.

Black hypertensive patients generally respond better to monotherapy with calcium-channel blockers or thiazide diuretics than to other antihypertensive drug classes (e.g., ACE inhibitors, angiotensin II receptor antagonists). However, the combination of an ACE inhibitor or an angiotensin II receptor antagonist with a calcium channel blocker or thiazide diuretic produces similar BP lowering in black patients as in other racial groups.

Hypertrophic Cardiomyopathy

Has been used as adjunctive therapy in the management of hypertrophic cardiomyopathy.

Recommended only when no other suitable agents are available. (See Hypertrophic Cardiomyopathy under Cautions.)

Acute MI

Used in the early treatment and secondary prevention of acute MI; an effective anti-ischemic agent, but mortality benefit not demonstrated.

Calcium-channel blockers generally are used for their anti-ischemic and BP-reducing properties in the MI setting, and only when β-blockers (which have been shown to reduce mortality after MI) are ineffective, not tolerated, or contraindicated.

Experts state that calcium-channel blockers may be used to relieve ischemic symptoms, lower BP, or control rapid ventricular response rate associated with atrial fibrillation in patients with ST-segment-elevation MI (STEMI) who are intolerant to β-blockers.

Experts recommend a nondihydropyridine calcium-channel blocker for ongoing or recurrent ischemia in patients with non-ST-segment-elevation MI (NSTEMI) who have a contraindication to β-blockers and who do not have clinically important left ventricular dysfunction, increased risk of cardiogenic shock, or AV block.

Bipolar Disorder

Has been used for management of manic manifestations of bipolar disorder; other more effective agents (e.g., lithium) available.