Hypotension levodopa causing

Side effects include dyskinesias, orthostatic hypotension, dizziness, nausea, insomnia, sleep attacks, pathologic gambling, discoloration of urine/sweat, and psychiatric effects (confusion, hallucinations, nightmares, and altered behavior). Dyskinesias caused by adding other PD drugs to levodopa may be improved by decreasing the levodopa dose. Motor complications occur in about 40% of patients within 4 to 6 years of starting levodopa.1,8,24,25,37... 

L-Dopa. Dopamine itself cannot penetrate the blood-brain barrier however, its natural precursor, L-dihydroxy-phenylalanine (levodopa), is effective in replenishing striatal dopamine levels, because it is transported across the blood-brain barrier via an amino acid carrier and is subsequently decarboxy-lated by DOPA-decarboxylase, present in striatal tissue. Decarboxylation also takes place in peripheral organs where dopamine is not needed, likely causing undesirable effects (tachycardia, arrhythmias resulting from activation of Pi-adrenoceptors [p. 114], hypotension, and vomiting). Extracerebral production of dopamine can be prevented by inhibitors of DOPA-decarboxylase (car-bidopa, benserazide) that do not penetrate the blood-brain barrier, leaving intracerebral decarboxylation unaffected. Excessive elevation of brain dopamine levels may lead to undesirable reactions, such as involuntary movements (dyskinesias) and mental disturbances. 

Quazepam (Doral) [C IV] [Sedative/Hypnotic/ Benzodiazepine] Uses Insomnia Action Benzodiazepine Dose 7.5-15 mg PO hs PRN i in elderly hqjatic failure Caution [X, /-] NA glaucoma Contra PRG, sleep apnea Disp Tabs SE Sedation, hangovCT, somnolence, resp depression Interactions T Effects W/ azole antifungals, cimetidine, digoxin, disulfiram, INH, levodopa, macrolides, neuroleptics, phenytoin, quinolones, SSRIs, verapamil, grapefruit juice, EtOH effects W/carbamazepine, rifampin, rifabutin, tobacco EMS Use caution w/ other benzodiazepines, antihistamines, opioids and verapamil, can T CNS depression concurrent EtOH and grapefruit juice use T CNS depression OD May cause profound CNS depression, confusion, bradycardia, hypotension, and altered reflexes flumazenil can be used as antidote activated charcoal may be effective... 

WARNING Cases of fulminant liver failure resulting in death have occurred Uses Adjunct to carbidopa/levodopa in Parkinson Dz Action COMT inhibitor slows levodopa metabolism Dose 100 mg PO tid w/ 1st daily levodopa/carbidopa dose, then dose 6 12 h later -1- w/ renal impair Caution [C, ] Contra Hqjatic impair, w/ nonselective MAOI Disp Tabs SE Constipation, XCTOstomia, vivid dreams, hallucinations, anorexia, N/D, orthostasis, liver failure, Rhabdomyolysis Interactions T Effects OF CNS dqjressants, SSRIs, TCAs, warfarin, EtOH t risk of hypotensive crisis W/ nonselective MAOIs (phenelzine, tranylc5 promine) EMS Has been associated w/ liver failure and death may experience hallucinations concurrent EtOH use can T CNS dqjression T effects of warfarin severe D is common sevoal wks afto starting OD May cause NA and dizziness... 

Adverse effects of the COMT inhibitors relate in part to increased levodopa exposure and include dyskinesias, nausea, and confusion. It is often necessary to lower the daily dose of levodopa by about 30% in the first 48 hours to avoid or reverse such complications. Other adverse effects include diarrhea, abdominal pain, orthostatic hypotension, sleep disturbances, and an orange discoloration of the urine. Tolcapone may cause an increase in liver enzyme levels and has been associated... 

Methyldopa [Aldomet) [Antihypertensive/Centrally Acting Antiadrenergic] Uses HTN Action Centrally acting antihypertensive Dose Adults. 250-500 mg PO bid-dd (max 2-3 g/d) or 250 mg-1 g IV q6-8h Peds. 10 mg/kg/24 h PO in 2-3 + doses (max 40 mg/kg/24 h - q6-l2h) or 5-10 mg/kg/dose IV q6-8h to total dose of 20—40 mg/kg/24 h i in renal insuff/elderly Caution [B (PO), C (IV), +] Contra Liver Dz MAOIs Disp Tabs, inj SE Discolors urine inidal transient sedadon/drowsiness frequent, edema, hemolydc anemia, hepadc disorders Interactions T Effects W/ anesthetics, diuredcs, levodopa, Li, methotrimeprazine, thioxanthenes, vasodilators, verapamil T effects OF haloperidol, Li, tolbutamide 1 effects W7amphetamines, Fe, phenothiazine, TCAs 1 effects OF ephedrine EMS Use diuredcs, verapamil, and sympathomimedcs w/ caudon may T risk hypotension, arrhythmias and pressors effects OD May cause profound hypotension, drowsiness, and impaired myocardial conduction activated charcoal may be effective... 

Adverse effects Diarrhea is the most common side effect of tolcapone. As expected, /evocfopa-related adverse effects increase when tolcapone is added. These include postural hypotension, nausea, sleep disorders, anorexia, dyskinesias, and hallucinations. Most seriously, fulminating hepatic necrosis is associated with tolcapone use. Baseline and frequent, regular determinations of hepatic serum enzymes are suggested by the manufacturer. Any elevations above normal are cause for discontinuation. Because of the hepatotoxicity, tolcapone should only be used as an adjunct in patients on levodopa/carbidopa who are experiencing symptom fluctuations. 

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