V

V



valganciclovir hydrochloride


(val-gan-sye’-kloh-veer hye-droe-klor’-ide)


image Brand Name(s): Valcyte


Chemical Class: Acyclic purine nucleoside analog; ganciclovir derivative

image Clinical Pharmacology:


Mechanism of Action: A synthetic nucleoside that competes with viral DNA esterases and is incorporated directly into growing viral DNA chains. Therapeutic Effect: Interferes with DNA synthesis and viral replication.

Pharmacokinetics: Well absorbed and rapidly converted to ganciclovir by intestinal and hepatic enzymes. Widely distributed. Slowly metabolized intracellularly. Primarily excreted unchanged in urine. Removed by hemodialysis. Half-life: 18 hr (increased in impaired renal function).

image Available Forms:


• Tablets: 450 mg.

image Indications and Dosages:


Cytomegalovirus (CMV) retinitis in patients with normal renal function: PO Initially, 900 mg (two 450-mg tablets) twice a day for 21 days. Maintenance: 900 mg once a day.

Prevention of CMV after transplant: PO 900 mg once a day beginning within 10 days of transplant and continuing until 100 days post-transplant.

Dosage in renal impairment: Dosage and frequency are modified based on creatinine clearance.
























Creatinine Clearance Induction Dosage Maintenance Dosage
60 ml/min or higher 900 mg twice a day 900 mg once a day
40–59 ml/min 450 mg twice a day 450 mg once a day
25–39 ml/min 450 mg once a day 450 mg every 2 days
10–24 ml/min 450 mg every 2 days 450 mg twice a wk

image Contraindications: Hypersensitivity to acyclovir or ganciclovir



image Side Effects


Frequent (16%-9%)


Diarrhea, neutropenia, headache

Occasional (8%-3%)


Nausea, anemia, thrombocytopenia

Rare (less than 3%)


Insomnia, paresthesia, vomiting, abdominal pain, fever


image Serious Reactions



• Hematologic toxicity, including severe neutropenia (most common), anemia, and thrombocytopenia, may occur.

• Retinal detachment occurs rarely.

• An overdose may result in renal toxicity.

• Valganciclovir may decrease sperm production and fertility.


image Patient/Family Education



• Take with food

• Men should use a condom during sexual activity while using this medicine for at least 3 mo after treatment ends because valganciclovir interferes with normal sperm formation


image Monitoring Parameters



• CBC, platelet count, creatinine

image Geriatric side effects at a glance:


image CNS

image Bowel Dysfunction

image Bladder Dysfunction

image Falls


image U.S. Regulatory Considerations



image FDA Black Box
• Valganciclovir is metabolized to ganciclovir. Risk of granulocytopenia, anemia, and thrombocytopenia. Aspermatogenesis, carcinogenic, teratogenic in animals.

• Oral capsules of ganciclovir have been associated with the risk of rapid-rate CMV retinitis progression and should be used as a maintenance therapy only in patients who benefit from avoiding daily intravenous infusions.

image OBRA regulated in U.S. Long Term Care


valproic acid/valproate sodium/divalproex sodium


(val-proe’-ik as’-id/val-proe’-ate soe’-dee-um/di-val’-pro-eks soe’-dee-um)


image Brand Name(s): (valproic acid) Depakene


image Brand Name(s): (valproate sodium) Depakene syrup


image Brand Name(s): (divalproex sodium) Depacon, Depakote, Depakote ER, Depakote Sprinkle


Chemical Class: Carboxylic acid derivative

image Clinical Pharmacology:


Mechanism of Action: An anticonvulsant that directly increases concentration of the inhibitory neurotransmitter gamma-aminobutyric acid. Therapeutic Effect: Reduces seizure activity.

Pharmacokinetics: Well absorbed from the GI tract. Protein binding: 80%-90%. Metabolized in the liver. Primarily excreted in urine. Not removed by hemodialysis. Half-life: 6-16 hr (may be increased in hepatic impairment, the elderly, and children younger than 18 mo).

image Available Forms:


• Capsules (Depakene): 250 mg.

• Syrup (Depakene): 250 mg/5 ml.

• Tablets (Delayed-Release [Depakote]): 125 mg, 250 mg, 500 mg.

• Tablets (Extended-Release [Depakote ER]): 250 mg, 500 mg.

• Capsules Sprinkles (Depakote Sprinkle): 125 mg.

• Injection (Depacon): 100 mg/ml.

image Indications and Dosages:


Seizures: PO Initially, 10-15 mg/kg/day in 1-3 divided doses. May increase by 5-10 mg/kg/day at weekly intervals up to 30-60 mg/kg/day. Usual adult dosage: 1,000-2,500 mg/day. IV Same as oral dose but given q6h.

Manic episodes: PO Initially, 750 mg/day in divided doses. Maximum: 60 mg/kg/day.

Prevention of migraine headaches: PO (Extended-Release) Initially, 500 mg/day for 7 days. May increase up to 1,000 mg/day. PO (Delayed-Release) Initially, 250 mg twice a day. May increase up to 1,000 mg/day.

image Unlabeled Uses: Prevention of migraine; treatment of behavior disorders in Alzheimer’s disease; bipolar disorder; chorea, myoclonic, simple partial, and tonic-clonic seizures; organic brain syndrome; schizophrenia; status epilepticus; tardive dyskinesia


image Contraindications: Active hepatic disease, urea cycle disorders




image Side Effects


Frequent


Epilepsy: Abdominal pain, diarrhea, transient alopecia, indigestion, nausea, vomiting, tremors, weight gain or loss


Mania (22%-19%): Nausea, somnolence


Occasional


Epilepsy: Constipation, dizziness, drowsiness, headache, skin rash, unusual excitement, restlessness


Mania (12%-6%): Asthenia, abdominal pain, dyspepsia (heartburn, indigestion, epigastric distress), rash


Rare


Epilepsy: Mood changes, diplopia, nystagmus, spots before eyes, unusual bleeding or ecchymosis



image Serious Reactions



• Alert Hepatotoxicity may occur, particularly in the first 6 mo of valproic acid therapy. It may be preceded by loss of seizure control, malaise, weakness, lethargy, anorexia, and vomiting rather than abnormal serum liver function test results.

• Blood dyscrasias may occur.


image Patient/Family Education



• Administer with food to decrease GI side effects

• Do not administer with carbonated beverages or milk


image Monitoring Parameters



• Therapeutic levels (draw just before next dose) 50-100 mcg/ml

• ALT, AST, coagulation studies, and platelet count prior to and during therapy, especially first 6 mo

• Minor elevations in ALT, AST are frequent and dose related

image Geriatric side effects at a glance:


image CNS

image Bowel Dysfunction

image Bladder Dysfunction

image Falls Other: Tremor, osteoporosis

image Use with caution in older patients with: Hepatic impairment, End-stage renal disease, Osteoporosis, Parkinsonism, Essential tremor, Unsteady gait, Urinary incontinence



image U.S. Regulatory Considerations



image FDA Black Box

Hepatotoxicity, pancreatitis, teratogenicity


image OBRA regulated in U.S. Long Term Care

image Other Uses in Geriatric Patient: Bipolar Disorder, Mania, Agitation in Dementia


image Side Effects:


Of particular importance in the geriatric patient: delirium, confusion, cognitive impairment, amnesia, somnolence, reduction in bone mineral density, alopecia, tremor, weight gain, reversible parkinsonism, thrombocytopenia

image Geriatric Considerations–Summary: Valproic acid is a first-line treatment for partial or generalized seizures in older adults. Elimination half-life is doubled in older adults due to a larger volume of distribution. Serum concentrations are not correlated with behavior response and poorly correlated with CNS side effects. Tremor and parkinsonism tend to be dose-dependent. Sedation and gait disturbances are more likely with rapid titration. Ataxia and cognitive impairment occur less frequently than with phenytoin or carbamazepine. Valproic acid may reduce bone mineral density by interfering with osteoblastic function. Calcium and vitamin D supplementation and monitoring of bone mineral density is recommended for older adults taking valproate. Divalproex formulation is generally better tolerated than valproic acid.



Reference



1 Brodie M, Kwan P. Epilepsy in elderly people. BMJ. 2005;331:1317-1322.


2 Birnbaum AK, Hardie NA, Conway JM, et al. Valproic acid doses, concentrations, and clearances in elderly nursing home residents. Epilepsy Res. 2004;62:157-162.


3 Arroyo S, Kramer G. Treating epilepsy in the elderly: safety considerations. Drug Saf. 2001;24:991-1015.


4 Drugs that may cause cognitive disorders in the elderly. Med Let. 2000;42:111-112.


5 Faught E. Epidemiolgy and drug treatment of epilepsy in elderly people. Drugs Aging. 1999;15:255-269.



valsartan


(val-sar’-tan)


image Brand Name(s): Diovan


Combinations

Rx: with hydrochlorothiazide (Diovan HCT)

Chemical Class: Angiotensin II receptor antagonist

image Clinical Pharmacology:


Mechanism of Action: An angiotensin II receptor, type AT1, antagonist that blocks vasoconstrictor and aldosterone-secreting effects of angiotensin II, inhibiting the binding of angiotensin II to the AT1 receptors. Therapeutic Effect: Causes vasodilation, decreases peripheral resistance, and decreases BP.

Pharmacokinetics: Poorly absorbed after PO administration. Food decreases peak plasma concentration. Protein binding: 95%. Metabolized in the liver. Recovered primarily in feces and, to a lesser extent, in urine. Unknown if removed by hemodialysis. Half-life: 6 hr.

image Available Forms:


• Tablets: 40 mg, 80 mg, 160 mg, 320 mg.

image Indications and Dosages:


Hypertension: PO Initially, 80-160 mg/day in patients who are not volume depleted. May increase up to a maximum: 320 mg/day.

CHF: PO Initially, 40 mg twice a day. May increase up to 160 mg twice a day. Maximum: 320 mg/day.

Post heart attack: PO Initially, 20 mg twice a day. May increase within 7 days to 40 mg twice a day. May further increase up to target dose of 160 mg twice a day.

image Unlabeled Uses: Diabetic nephropathy


image Contraindications: Bilateral renal artery stenosis, biliary cirrhosis or obstruction, hypoaldosteronism, severe hepatic impairment



image Side Effects


Rare (2%-1%)


Insomnia, fatigue, heartburn, abdominal pain, dizziness, headache, diarrhea, nausea, vomiting, arthralgia, edema


image Serious Reactions



• Overdosage may manifest as hypotension and tachycardia. Bradycardia occurs less often.

• Viral infection and upper respiratory tract infection (cough, pharyngitis, sinusitis, rhinitis) occur rarely.

• Hypoglycemia may occur in patients with diabetes using glucose-lowering drugs.


Special Considerations



• Potentially as or more effective than angiotensin-converting enzyme inhibitors, without cough; no evidence for reduction in morbidity and mortality as first-line agents in hypertension, yet; whether they provide the same cardiac and renal protection also still tentative; like ACE inhibitors, less effective in black patients


image Patient/Family Education



• Call your clinician immediately if note following side effects: wheezing; lip, throat, or face swelling; hives or rash

• Female patients should be aware of the consequences of second- and third-trimester exposure to valsartan

• Valsartan must be taken for the rest of his or her life to control hypertension

• Do not exercise outside during hot weather because of the risks of dehydration and hypotension


image Monitoring Parameters



• Baseline electrolytes, urinalysis, BUN and creatinine with recheck at 2-4 wk after initiation (sooner in volume-depleted patients); monitor sitting blood pressure; watch for symptomatic hypotension, particularly in volume-depleted patients

• Assess for signs and symptoms of an upper respiratory tract infection

image Geriatric side effects at a glance:


image CNS

image Bowel Dysfunction

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Jun 8, 2016 | Posted by in GERIATRICS | Comments Off on V

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