verapamil hydrochloride

verapamil hydrochloride

(ver ap' a mill)

Calan, Calan SR, Covera-HS, Isoptin SR, Verelan, Verelan PM

Pregnancy Category C

Drug classes

Calcium channel-blocker

Antianginal

Antiarrhythmic

Antihypertensive

Therapeutic actions

Inhibits the movement of calcium ions across the membranes of cardiac and arterial muscle cells; calcium is involved in the generation of the action potential in specialized automatic and conducting cells in the heart, in arterial smooth muscle, and in excitation-contraction coupling in cardiac muscle cells; inhibition oftransmembrane calcium flow results in the depression of impulse formation in specialized cardiac pacemaker cells, slowing of the velocity of conduction of the cardiac impulse, the depression of myocardial contractility, and the dilation of coronary arteries and arterioles and peripheral arterioles; these effects lead to decreased cardiac work, decreased cardiac energy consumption, and in patients with vasospastic (Prinzmetal's) angina, increased delivery of oxygen to myocardial cells.

Indications

·        Angina pectoris due to coronary artery spasm (Prinzmetal's variant angina)

·        Effort-associated angina

·        Chronic stable angina

·        Unstable, crescendo, preinfarction angina

·        Essential hypertension

·        Parenteral: Treatment of supraventricular tachyarrhythmias

·        Parenteral: Temporary control of rapid ventricular rate in atrial flutter or atrial fibrillation

Contraindications and cautions

·        Contraindicated with allergy to verapamil; sick sinus syndrome, except with ventricular pacemaker; heart block (second- or third-degree); hypotension; pregnancy; lactation.

·        Use cautiously with idiopathic hypertrophic subaortic stenosis, cardiogenic shock, severe CHF, impaired renal or hepatic function, and in patients with atrialflutter or atrial fibrillation and an accessory to bypass tract.

Available forms

Tablets—40, 80, 120 mg; SR tablets—120, 180, 240 mg; ER tablets—120, 180, 240 mg; SR capsules—120, 180, 240, 360 mg; injection—2.5 mg/mL; ER capsules—100, 120, 180, 200, 240, 300, 360 mg

Dosages

ADULTS

Oral

Immediate release

·        Angina: 80 mg q 6–8 hr; may increase by 80 mg at weekly intervals until control is achieved. Maintenance 240–480 mg daily.

·        Arrhythmias: 240–480 mg/day. In digitalized adults: 240–320 mg/day.

·        Hypertension: 40 mg to 80 mg PO tid.

ER

·        Capsules: 120–240 mg/day PO in the morning. Titrate dose to a maximum 480 mg/day.

·        Tablets: 120–180 mg/day PO in the morning. Titrate to a maximum 240 mg q 12 hr.

SR

·        120–180 mg/day PO. Titrate up to a maximum 480 mg PO in the morning.

Parenteral

IV use only. Initial dose, 2.5–10 mg over 2 min; may repeat dose of 10 mg 30 min after first dose if initial response is inadequate.

PEDIATRIC PATIENTS

IV

< 1 yr: Initial dose, 0.1–0.2 mg/kg over 2 min.

1–15 yr: Initial dose, 0.1–0.3 mg/kg over 2 min. Do not exceed 5 mg. Repeat above dose 30 min after initial dose if response is not adequate. Repeat dose should not exceed 10 mg.

GERIATRIC PATIENTS OR PATIENTS WITH RENAL IMPAIRMENT

Reduce dosage, and monitor patient response carefully. Give IV doses over 3 min to reduce risk of serious side effects. Administer IV doses very slowly, over 2 min.

Pharmacokinetics

Route	Onset	Peak	Duration
Oral	30 min	1–2.2 hr	3–7 hr
IV	1–5 min	3–5 min	2 hr

Metabolism: Hepatic; T_1/2: 3–7 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Urine

IV facts

Preparation: No further preparation required.

Infusion: Infuse very slowly over 2–3 min.

Y-site incompatibilities: Do not give with albumin, ampicillin, nafcillin, oxacillin, sodium bicarbonate, amphotericin B, hydralazine, aminophylline.

Adverse effects

·        CNS: Dizziness, vertigo, emotional depression, sleepiness, headache

·        CV: Peripheral edema, hypotension, arrhythmias, bradycardia; AV heart block

·        GI: Nausea, constipation

·        Other: Muscle fatigue, diaphoresis, rash

Interactions

Drug-drug

·        WARNING: Risk of serious cardiac effects with IV beta-adrenergic blocking agents; do not give these drugs within 48 hr before or 24 hr after IVverapamil

·        Increased cardiac depression with beta-adrenergic blocking agents

·        Additive effects of verapamil and digoxin to slow AV conduction

·        Increased serum levels of digoxin, carbamazepine, prazosin, quinidine

·        Increased respiratory depression with atracurium, gallamine, pancuronium, tubocurarine, vecuronium

·        Decreased effects with calcium, rifampin

Drug-food

·        Decreased metabolism and risk of toxic effects if combined with grapefruit juice; avoid this combination

Nursing considerations

Assessment

·        History: Allergy to verapamil; sick sinus syndrome; heart block; IHSS; cardiogenic shock, severe CHF; hypotension; impaired hepatic or renal function; pregnancy, lactation

·        Physical: Skin color, edema; orientation, reflexes; P, BP, baseline ECG, peripheral perfusion, auscultation; R, adventitious sounds; liver evaluation, normal output; LFTs, renal function tests, urinalysis

Interventions

·        WARNING: Monitor patient carefully (BP, cardiac rhythm, and output) while drug is being titrated to therapeutic dose. Dosage may be increased more rapidly in hospitalized patients under close supervision.

·        Ensure that patient swallows SR tablets whole; patient should not cut, crush, or chew them.

·        Monitor BP very carefully with concurrent doses of antihypertensives.

·        Monitor cardiac rhythm regularly during stabilization of dosage and periodically during long-term therapy.

·        Administer SR form in the morning with food to decrease GI upset.

·        Protect IV solution from light.

·        Monitor patients with renal or hepatic impairment carefully for possible drug accumulation and adverse reactions.

Teaching points

·        Take sustained-release form in the morning with food; swallow it whole, do not cut, crush, or chew it. Do not drink grapefruit juice while using this drug.

·        You may experience these side effects: Nausea, vomiting (eat frequent small meals); headache (adjust lighting, noise, and temperature; request medication); dizziness, sleepiness (avoid driving or operating dangerous equipment); emotional depression (reversible); constipation (request aid).

·        Report irregular heartbeat, shortness of breath, swelling of the hands or feet, pronounced dizziness, nausea, constipation.

Adverse effects in Italic are most common; those in Bold are life-threatening.

venlafaxine hydrochloride

venlafaxine hydrochloride

(vin lah facks' in)

Effexor, Effexor XR

Pregnancy Category C

Drug class

Antidepressant

Anxiolytic

Therapeutic actions

Potentiates the neurotransmitter activity in the CNS; inhibits serontonin, norepinephrine, and dopamine reuptake leading to prolonged stimulation at neuroreceptors.

Indications

·        Treatment of major depressive disorder

·        Treatment of panic disorder, with or without agoraphobia

·        Treatment of generalized anxiety disorder (extended release—ER only)

·        Treatment of social anxiety disorder (ER only)

·        Unlabeled uses: PMDD, hot flushes, PTSD

Contraindications and cautions

·        Contraindicated with allergy to venlafaxine, use of MAOIs within last 14 days.

·        Use cautiously with pregnancy, lactation, patients whose underlying medical condition might be compromised by increased heart rate (hyperthyroidism, CHF, recent MI).

Available forms

Tablets—25, 37.5, 50, 75, 100 mg; ER capsules—37.5, 75, 150 mg

Dosages

ADULTS

·        Depression: Starting dose, 75 mg/day PO in two to three divided doses (or once a day, ER capsule) taken with food. May be increased slowly up to 225 mg/day to achieve desired effect, maximum dose 375 mg/day in three divided doses.

·        Transfer to or from MAOI: At least 14 days should elapse from the discontinuation of the MAOI and the starting of venlafaxine; allow at least 7 days to elapse from the stopping of venlafaxine to the starting of an MAOI.

·        Generalized anxiety disorder/Social anxiety: 75–225 mg/day PO should be taken on a daily basis, not as needed (ER only).

·        Panic disorder: 37.5 mg/day PO for 7 days, then increase based on patient response to 75 mg/day for 7 days, and then 75 mg/day weekly increases to a maximum of 225 mg/day.

PEDIATRIC PATIENTS

Safety and efficacy not established.

PATIENTS WITH RENAL OR HEPATIC IMPAIRMENT

For patients with creatinine clearance of 10–70 mL/min, reduce dosage by 25%–50%. For patients on dialysis, reduce dosage by 50% (give after dialysis completion on dialysis days). For patients with hepatic impairment, reduce total daily dose by 50%, and increase very slowly to achieve desired effect.

Pharmacokinetics

Route	Onset	Duration
Oral	Slow	48 hr

Metabolism: Hepatic; T_1/2: 1.3–2 hr

Distribution: Crosses placenta; may enter breast milk

Excretion: Urine

Adverse effects

·        CNS: Somnolence, dizziness, insomnia, nervousness, anxiety, tremor, dreams

·        CV: Vasodilation, hypertension, tachycardia

·        Dermatologic: Sweating, rash, pruritus

·        GI: Nausea, constipation, anorexia, diarrhea, vomiting, dyspepsia, dry mouth, flatulence

·        GU: Abnormal ejaculation, impotence, urinary frequency

·        Other: Headache, asthenia, infection, chills, chest pain

Interactions

Drug-drug

·        Increased serum levels and risk of toxicity with MAOIs (within last 14 days), cimetidine

·        Serotonin syndrome may occur if combined with trazodone

·        Increased sedation with alcohol

Drug-alternative therapy

·        Increased sedation and hypnotic effects with St. John's wort

Nursing considerations

Assessment

·        History: Allergy to venlafaxine; use of MAOIs within last 14 days; pregnancy, lactation

·        Physical: Skin color, T, lesions; reflexes, gait, sensation, cranial nerve evaluation; mucous membranes, abdominal examination, normal output; P, BP, peripheral perfusion

Interventions

·        Give with food to decrease GI effects.

·        Advise patient to use contraceptives.

·        Monitor patient for suicidal ideation, especially when beginning therapy or changing dosage.

Teaching points

·        Take with food to decrease GI upset.

·        Avoid alcohol while using this drug.

·        This drug cannot be taken during pregnancy; use birth control. If you become pregnant, consult with your health care provider.

·        You may experience these side effects: Loss of appetite, nausea, vomiting, dry mouth (use frequent mouth care, eat frequent small meals, suck sugarless lozenges); constipation (request bowel program); dizziness, drowsiness, tremor (avoid driving or operating dangerous machinery).

·        Report rash, hives, increased depression, pregnancy.

Adverse effects in Italic are most common; those in Bold are life-threatening.

vardenafil hydrochloride

vardenafil hydrochloride

(var den' ah fill)

Levitra

Pregnancy Category B

Drug classes

Impotence drug

Phosphodiesterase type 5 inhibitor

Therapeutic actions

Selectively inhibits cGMP-specific phosphodiesterase type 5. The mechanism of penile erection involves the release of nitric oxide into the corpus cavernosum of the penis during sexual stimulation. Nitrous oxide activates cGMP, which causes smooth muscle relaxation allowing the flow of blood into the corpus cavernosum. Vardenafil prevents the breakdown of cGMP by phosphodiesterase, leading to increased cGMP levels and prolonged smooth muscle relaxation promoting the flow of blood into the corpus cavernosum.

Indications

·        Treatment of erectile dysfunction occurring in the presence of sexual stimulation

Contraindications and cautions

·        Contraindicated with allergy to any component of the tablet, for women or children; concurrent use of nitrates or alpha blockers

·        Use cautiously with hepatic or renal dysfunction; with anatomic deformation of the penis, with known cardiac disease (effects of sexual activity need to be evaluated), congenital prolonged QT interval, unstable angina; hypotension (systolic < 90); uncontrolled hypertension (> 170/110), severe hepatic impairment; end stage renal disease with dialysis; hereditary degenerative retinal disorders.

Available forms

Tablets—2.5, 5, 10, 20 mg

Dosages

ADULTS

5–10 mg PO taken 1 hr before anticipated sexual activity; range 5–20 mg PO. Limit use to once per day.

PEDIATRIC PATIENTS

Not intended for use in children.

GERIATRIC PATIENTS AND THOSE WITH MODERATE HEPATIC IMPAIRMENT

Starting dose of 5 mg PO is suggested.

Pharmacokinetics

Route	Onset	Peak
Oral	Rapid	30–120 min

Metabolism: Hepatic, T_1/2 : 4–5 hr

Distribution: Not intended for use in women, no clear studies on crossing the placenta or entering breast milk

Excretion: Feces

Adverse effects

·        CNS: Headache, abnormal vision, dizziness, hypertonia, insomnia, somnolence, vertigo, ischemic optic neuropathy

·        CV: Flushing, angina, chest pain, hypertension, hypotension, MI, palpitation, postural hypotension, tachycardia

·        GI: Dyspepsia, diarrhea, abdominal pain, dry mouth, esophagitis, gastritic, GERD

·        GU: Abnormal ejaculation, priapism

·        Respiratory: Rhinitis, sinusitis, dyspnea, epistaxis, pharyngitis

·        Other: Flulike syndrome, edema, pain, rash, sweating

Interactions

Drug-drug

·        WARNING: Possible severe hypotension and serious cardiac events if combined with nitrates, alpha blockers; this combination must be avoided.

·        Possible increased vardenafil levels and effects if taken with ketoconazole, itraconazole, erythromycin; monitor patient and reduce dosage as needed

·        Increased vardenafil serum levels if combined with indinavir, ritonavir; if these drugs are being used, limit vardenafil dose to 2.5 mg in a 24-hr period

Nursing considerations

Assessment

·        History: Allergy to any component of the tablet, concurrent use of nitrates or alpha blockers; unstable angina; hypotension; uncontrolled hypertension; severe hepatic impairment; end-stage renal disease with dialysis; hereditary degenerative retinal disorders; anatomical deformation of the penis, cardiac disease, congenital prolonged QT interval

·        Physical: Orientation, affect; skin color, lesions; R, adventitious sounds; P, BP, ECG, LFTs, renal function tests

Interventions

·        Ensure diagnosis of erectile dysfunction and determine underlying causes and other appropriate treatment.

·        Advise patient that drug does not work without sexual stimulation. Limit use to once per day.

·        Remind patient that drug does not protect against sexually transmitted diseases and appropriate measures should be taken.

·        WARNING: Advise patient to never take this drug with nitrates or alpha blockers; serious and even fatal complications can occur.

Teaching points

·        Take this drug 60 minutes before anticipated sexual activity. The drug will have no effect unless there is sexual stimulation.

·        This drug will not protect you from sexually transmitted diseases; use appropriate precautions.

·        Do not take this drug if you are taking any nitrates or alpha blockers; serious side effects or death can occur.

·        Many drugs may interact with vardenafil; always consult your health care provider before taking any drug, including over-the-counter drugs and herbal therapies; dosage adjustments may be needed.

·        You may experience these side effects: Headache, dizziness, upset stomach, runny nose; these side effects should go away within a couple of hours. If side effects persist, consult your health care provider.

·        Stop drug and consult your health care provider immediately if you experience sudden loss of vision.

·        Report difficult or painful urination, vision changes, fainting, erection that persists for longer than 4 hours, sudden loss of vision.

Adverse effects in Italic are most common; those in Bold are life-threatening.

valsartan

valsartan

(val sar' tan)

Diovan

Pregnancy Category C (first trimester)

Pregnancy Category D (second and third trimesters)

Drug classes

Angiotensin II receptor blocker

Antihypertensive

Therapeutic actions

Selectively blocks the binding of angiotensin II to specific tissue receptors found in the vascular smooth muscle and adrenal gland; this action blocks thevasoconstricting effect of the renin–angiotensin system as well as the release of aldosterone, leading to decreased BP; may prevent the vessel remodeling associated with the development of atherosclerosis.

Indications

·        Treatment of hypertension, alone or in combination with other antihypertensives

·        Treatment of heart failure in patients who are intolerant of ACE inhibitors

Contraindications and cautions

·        Contraindicated with hypersensitivity to valsartan, pregnancy (use during second or third trimester can cause injury or even death to fetus), lactation.

·        Use cautiously with hepatic or renal dysfunction, hypovolemia.

Available forms

Tablets—40, 80, 160, 320 mg

Dosages

ADULTS

·        Hypertension: 80 mg PO daily; range 80–320 mg/day.

·        Heart failure: Starting dose is 40 mg bid, titration to 80 mg and 160 mg bid should be done to the highest dose, as tolerated by the patient. Maximum daily dose is 320 mg daily given in divided doses. Concomitant use with an ACE inhibitor and a beta blocker is not recommended.

·        Post-MI left ventricular dysfunction: Start as early as 12 hr post-MI; 20 mg PO bid, may increase after 7 days to 40 mg PO bid; titrate to 160 mg PO bid if tolerated.

PEDIATRIC PATIENTS

Safety and efficacy not established.

PATIENTS WITH HEPATIC OR RENAL IMPAIRMENT

Exercise caution and monitor patient frequently.

Pharmacokinetics

Route	Onset	Peak
Oral	Varies	2–4 hr

Metabolism: Hepatic; T_1/2: 6 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Feces and urine

Adverse effects

·        CNS: Headache, dizziness, syncope, muscle weakness

·        CV: Hypotension

·        Dermatologic: Rash, inflammation, urticaria, pruritus, alopecia, dry skin

·        GI: Diarrhea, abdominal pain, nausea, constipation, dry mouth, dental pain

·        Respiratory: URI symptoms, cough, sinus disorders

·        Other: Cancer in preclinical studies, back pain, fever, gout, hyperkalemia

Nursing considerations

Assessment

·        History: Hypersensitivity to valsartan; pregnancy, lactation; hepatic or renal dysfunction; hypovolemia

·        Physical: Skin lesions, turgor; T; reflexes, affect; BP; R, respiratory auscultation; LFTs, renal function tests

Interventions

·        Administer without regard to meals.

·        WARNING: Ensure that patient is not pregnant before beginning therapy; suggest using barrier birth control while using drug; fetal injury and deaths have been reported.

·        Find alternative method of feeding infant if drug is being given to nursing mother. Depression of renin–angiotensin system in infants is potentially very dangerous.

·        WARNING: Alert surgeon and mark patient's chart that valsartan is being given. Blockage of renin–angiotensin system following surgery can produce problems. Hypotension may be reversed with volume expansion.

·        Monitor patient closely in any situation that may lead to decrease in BP secondary to reduction in fluid volume—excessive perspiration, dehydration, vomiting, diarrhea—as excessive hypotension can occur.

Teaching points

·        Take this drug without regard to meals. Do not stop taking drug without consulting your health care provider.

·        Use a barrier method of birth control while using this drug; if you become pregnant or desire to become pregnant, consult your health care provider.

·        You may experience these side effects: Dizziness (avoid driving or performing hazardous tasks); headache (medications may be available to help); nausea, vomiting, diarrhea (proper nutrition is important; consult a dietitian); symptoms of upper respiratory tract infection, cough (do not self-medicate; consult your health care provider if this becomes uncomfortable).

·        Report fever, chills, dizziness, pregnancy.

Adverse effects in Italic are most common; those in Bold are life-threatening.