quetiapine

kwe-tye-a-peen

(Seroquel)

 CLASSIFICATION

PHARMACOTHERAPEUTIC: Dibenzapine derivative. CLINICAL: Antipsychotic.

ACTION

A dibenzothiazepine derivative that antagonizes dopamine, serotonin, histamine, and alpha1-adrenergic receptors. Therapeutic Effect: Diminishes manifestations of psychotic disorders. Produces moderate sedation, few extrapyramidal effects, and no anticholinergic effects.

PHARMACOKINETICS

Well absorbed after PO administration. Protein binding: 83%. Widely distributed in tissues; CNS concentration exceeds plasma concentration. Undergoes extensive first-pass metabolism in the liver. Primarily excreted in urine. Half-life: 6 hr.

USES

Management of manifestations of psychotic disorders. Short-term treatment of acute manic episodes associated with bipolar disorder. OFF-LABEL: Autism, psychosis (children).

PRECAUTIONS

CONTRAINDICATIONS: None known. CAUTIONS: Alzheimer's dementia, history of breast cancer, cardiovascular disease (e.g., CHF, history of MI), cerebrovascular disease, hepatic impairment, dehydration, hypovolemia, history of drug abuse or dependence, seizures, hypothyroidism.

B LIFESPAN CONSIDERATIONS: Pregnancy/Lactation: Unknown if drug is distributed in breast milk. Not recommended for breast-feeding mothers. Pregnancy Category C. Children: Safety and efficacy not established. Elderly: No age-related precautions noted, but lower initial and target dosages may be necessary.

INTERACTIONS

DRUG: Alcohol, other CNS depressants: May increase CNS depression. Antihypertensives: May increase the hypotensive effects of these drugs. Hepatic enzyme inducers (such as phenytoin): May increase quetiapine clearance. HERBAL: None known. FOOD: None known. LAB VALUES: May decrease serum total and free thyroxine (T4) serum levels. May increase serum cholesterol, triglyceride, AST, and ALT levels. May produce a false-positive pregnancy test result.

AVAILABILITY (Rx)

TABLETS: 25 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg.

ADMINISTRATION/HANDLING

PO

N Adjust dosage at 2-day intervals. N Initial dose and dosage titration should occur at a lower dosage in elderly, patients with hepatic impairment, debilitated, or those predisposed to hypotensive reactions. N When restarting patients who have been off quetiapine for less than 1 wk, titration is not required and maintenance dose can be reinstituted. N When restarting patients who have been off quetiapine for longer than 1 wk, follow initial titration schedule. N Give without regard to food.

INDICATIONS/ROUTES/DOSAGE

TO MANAGE MANIFESTATIONS OF PSYCHOTIC DISORDERS

PO: ADULTS, ELDERLY: Initially, 25 mg twice a day, then 25U50 mg 2U3 times a day on the second and third days, up to 300U400 mg/day in divided doses 2U3 times a day by the fourth day. Further adjustments of 25U50 mg twice a day may be made at intervals of 2 days or longer. Maintenance: 300U800 mg/day (adults); 50U200 mg/day (elderly).

MANIA IN BIPOLAR DISORDER

PO: ADULTS, ELDERLY: Initially, 50 mg twice a day for 1 day. May increase in increments of 100 mg/day to 200 mg twice a day on day 4. May increase in increments of 200 mg/day to 800 mg/day on day 6. Range: 400U800 mg/day.

DOSAGE IN HEPATIC IMPAIRMENT, ELDERLY OR DEBILITATED PATIENTS, AND THOSE PREDISPOSED TO HYPOTENSIVE REACTIONS

These patients should receive a lower initial dose and lower dosage increases.

SIDE EFFECTS

FREQUENT (19%U10%): Headache, somnolence, dizziness. OCCASIONAL (9%U3%): Constipation, orthostatic hypotension, tachycardia, dry mouth, dyspepsia, rash, asthenia, abdominal pain, rhinitis. RARE (2%): Back pain, fever, weight gain.

ADVERSE REACTIONS/TOXIC EFFECTS

Overdose may produce heart block hypotension, hypokalemia, and tachycardia.

NURSING CONSIDERATION

BASELINE ASSESSMENT

Assess behavior, appearance, emotional status, response to environment, speech pattern, thought content. Obtain baseline CBC, hepatic enzyme levels before initiating treatment and periodically thereafter.

INTERVENTION/EVALUATION

Assist with ambulation if dizziness occurs. Supervise suicidal-risk patient closely during early therapy (as psychosis, depression lessens, energy level improves, increasing suicide potential). Monitor BP for hypotension. Assess pulse for tachycardia (especially with rapid increase in dosage). Assess bowel activity for evidence of constipation. Assess for therapeutic response (improved thought content, increased ability to concentrate, improvement in self-care). Eye exam to detect cataract formation should be obtained q6mo during treatment.

PATIENT/FAMILY TEACHING

N Avoid exposure to extreme heat. N Drink fluids often, especially during physical activity. N Take medication as ordered; do not stop taking or increase dosage. N Drowsiness generally subsides during continued therapy. N Avoid tasks that require alertness, motor skills until response to drug is established. N Avoid alcohol. N Change positions slowly to reduce hypotensive effect.

quinapril hydrochloride H

kwin-na-pril

(Accupril)

Do not confuse Accupril with Accolate or Accutane.

FIXED-COMBINATION(S)

Accuretic: quinapril/hydrochlorothiazide (a diuretic): 10 mg/12.5 mg; 20 mg/12.5 mg; 20 mg/25 mg.

 CLASSIFICATION

PHARMACOTHERAPEUTIC: Angiotensin-converting enzyme (ACE) inhibitor. CLINICAL: Antihypertensive.

ACTION

An ACE inhibitor that suppresses the renin-angiotensin-aldosterone system and prevents the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor; may also inhibit angiotensin II at local vascular and renal sites. Therapeutic Effect: Reduces peripheral arterial resistance, BP, and pulmonary capillary wedge pressure; improves cardiac output.

PHARMACOKINETICS

            Route Onset Peak  Duration      

            PO      1 hr     N/A    24 hr  

Readily absorbed from the GI tract. Protein binding: 97%. Metabolized in the liver, GI tract, and extravascular tissue to active metabolite. Primarily excreted in urine. Minimal removal by hemodialysis. Half-life: 1U2 hr; metabolite, 3 hr (increased in those with impaired renal function).

USES

Treatment of hypertension. Used alone or in combination with other antihypertensives. Adjunctive therapy in management of heart failure. OFF-LABEL: Treatment of hypertension and renal crisis in scleroderma, treatment of left ventricular dysfunction following MI.

PRECAUTIONS

CONTRAINDICATIONS: Bilateral renal artery stenosis, history of angioedema from previous treatment with ACE inhibitors. CAUTIONS: Renal impairment, CHF, collagen vascular disease, hypovolemia, renal stenosis, hyperkalemia.

B LIFESPAN CONSIDERATIONS: Pregnancy/Lactation: Crosses placenta. Unknown if distributed in breast milk. May cause fetal or neonatal mortality or morbidity. Pregnancy Category C (D if used in second or third trimester). Children: Safety and efficacy not established. Elderly: May be more sensitive to hypotensive effects.

INTERACTIONS

DRUG: Alcohol, antihypertensives, diuretics: May increase the effects of quinapril. Lithium: May increase lithium blood concentration and risk of lithium toxicity. NSAIDs: May decrease the effects of quinapril. Potassium-sparing diuretics, potassium supplements: May cause hyperkalemia. HERBAL: Garlic: May increase antihypertensive effect. Ginseng, yohimbe: May worsen hypertension. FOOD: None known. LAB VALUES: May increase BUN, serum alkaline phosphatase, serum bilirubin, serum creatinine, serum potassium, AST, and ALT levels. May decrease serum sodium levels. May cause positive antinuclear antibody titer.

AVAILABILITY (Rx)

TABLETS: 5 mg, 10 mg, 20 mg, 40 mg.

ADMINISTRATION/HANDLING

PO

N Give without regard to food. N Tablets may be crushed.

INDICATIONS/ROUTES/DOSAGE

HYPERTENSION (MONOTHERAPY)

PO: ADULTS: Initially, 10U20 mg/day. May adjust dosage at intervals of at least 2 wk or longer. Maintenance: 20U80 mg/day as single dose or 2 divided doses. Maximum: 80 mg/day. ELDERLY: Initially, 2.5U5 mg/day. May increase by 2.5U5 mg q1U2wk.

HYPERTENSION (COMBINATION THERAPY)

PO: ADULTS: Initially, 5 mg/day titrated to patient's needs. ELDERLY: Initially, 2.5U5 mg/day. May increase by 2.5U5 mg q1U2wk.

ADJUNCT TO MANAGE HEART FAILURE

PO: ADULTS, ELDERLY: Initially, 5 mg twice a day. Range: 20U40 mg/day.

DOSAGE IN RENAL IMPAIRMENT

Dosage is titrated to the patient's needs after the following initial doses:

            Creatinine Clearance      Initial Dose   

            More than 60 ml/min             10 mg      

            30U60 ml/min                         5 mg          

            10U29 ml/min                        2.5 mg        

SIDE EFFECTS

FREQUENT (7%U5%): Headache, dizziness. OCCASIONAL (4%U2%): Fatigue, vomiting, nausea, hypotension, chest pain, cough, syncope. RARE (less than 2%): Diarrhea, cough, dyspnea, rash, palpitations, impotence, insomnia, drowsiness, malaise.

ADVERSE REACTIONS/TOXIC EFFECTS

Excessive hypotension (“first-dose syncope”) may occur in patients with CHF and in those who are severely salt or volume depleted. Angioedema and hyperkalemia occur rarely. Agranulocytosis and neutropenia may be noted in those with collagen vascular disease, including scleroderma and systemic lupus erythematosus, and impaired renal function. Nephrotic syndrome may be noted in those with history of renal disease.

NURSING CONSIDERATION

BASELINE ASSESSMENT

Obtain BP immediately before each dose in addition to regular monitoring (be alert to fluctuations). If excessive reduction in BP occurs, place patient in supine position with legs slightly elevated. Renal function tests should be performed before beginning therapy. In patients with prior renal disease, urine test for protein by dipstick method should be made with first urine of day before beginning therapy and periodically thereafter. In those with renal impairment, autoimmune disease or in those taking drugs that affect leukocytes or immune response, CBC, differential count should be performed before beginning therapy and q2wk for 3 mo, then periodically thereafter.

INTERVENTION/EVALUATION

Monitor renal function, serum potassium, WBC. Assist with ambulation if dizziness occurs. Question for evidence of headache. Non-cola carbonated beverage, unsalted crackers, dry toast may relieve nausea.

PATIENT/FAMILY TEACHING

N To reduce hypotensive effect, rise slowly from lying to sitting position, permit legs to dangle from bed momentarily before standing. N Full therapeutic effect may take 1U2 wk. N Report any sign of infection (sore throat, fever). N Skipping doses or voluntarily discontinuing drug may produce severe rebound hypertension. N Avoid tasks that require alertness, motor skills until response to drug is established.