Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acyclovir given intravenously in either low dose (5 mg/kg every 8 h) or high dose (500 mg/m2 every 8 h) significantly reduced pain and accelerated skin healing in acute herpes zoster occurring in otherwise healthy adults. The higher dose also significantly reduced the duration of viral shedding. No significant effect on post-herpetic neuralgia could be demonstrated, although the higher dose showed a promising trend. No adverse effects were associated with the lower dose, but acyclovir at 500 mg/m2 resulted in nausea, vomiting and transiently elevated serum creatinine in a substantial number of patients.
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PMID:Acyclovir in shingles. 635 47

Acyclovir (ACV), a nucleoside analog that is a new herpes-specific antiviral drug, was given by gavage at 50, 150 and 450 mg/kg/day to Sprague Dawley rats and Swiss mice for most of their lifetime to assess chronic toxicity and carcinogenicity. Treatment with ACV did not shorten the lifespan of either rats or mice. In fact, female mice given 150 and 450 mg/kg/day had significantly longer mean durations of survival than control female mice when analyzed by the life table technique. There were no signs of toxicosis produced by chronic exposure to ACV in either the rats or mice, and there was no drug-related increase in neoplasms in either species. Four groups of Beagle dogs were initially given daily oral doses of 15, 45 or 150 mg/kg ACV in a 1 year chronic toxicity study. Dogs treated at 150 mg/kg/day vomited, had diarrhea, consumed less feed and lost weight within 2 weeks. Dogs treated at 45 mg/kg/day also had minimal signs of gastrointestinal toxicosis. These dose levels were then decreased to 60 and 30 mg/kg/day for the rest of the one year test period. With the exception of occasional and inconsistent emesis and diarrhea, the 60 mg/kg/day dose level was well tolerated. Some mid and high dose dogs had sore paws due to erosion of footpads and cracking, splitting and loosening of the nails first becoming evident during the 13th week of the study.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Preclinical toxicology studies with acyclovir: carcinogenicity bioassays and chronic toxicity tests. 666

Valaciclovir, the L-valyl ester of acyclovir, is rapidly and extensively converted in humans to acyclovir after oral administration by first-pass metabolism. A phase I study was conducted in two cohorts of volunteers with advanced human immunodeficiency virus (HIV) disease (absolute CD4 lymphocyte count of < 150 cells per microliters) who received oral valaciclovir at dosages of 1,000 or 2,000 mg four times daily for 30 days. All patients were clinically stable without any changes in underlying HIV-related medications for > or = 6 weeks prior to entry in study; these medications were continued throughout the study. Multiple-dose administration of valaciclovir showed a generally favorable safety profile. Nausea, vomiting, diarrhea, and abdominal pain each were reported in < or = 31% of the patients; of these symptoms, only one episode of diarrhea was considered causally related to valaciclovir exposure. Four patients developed neutropenia (two at each dose level) which was not clinically significant. There were no renal or neurologic adverse events. Valaciclovir was rapidly absorbed and converted to acyclovir, with plasma valaciclovir levels generally undetectable or levels of < or = 0.4 microgram/ml. After 3 h postdosing, valaciclovir was not detectable in plasma. Acyclovir was measurable in plasma as early as 15 min following valaciclovir dosing, and plasma concentrations of acyclovir greatly exceeded those of valaciclovir. The mean values for the maximum concentration of drug in plasma, time to maximum concentration of drug in plasma, area under the concentration-time curve from 0 h to infinity, and apparent half-life of acyclovir obtained after single- and multiple-dose valaciclovir administration in HIV-infected patients were similar to those reported in normal healthy volunteers. The time to maximum concentration in serum and half-life of acyclovir after valaciclovir administration were approximately 2 and 3 h, respectively, which were similar to those reported after oral administration of acyclovir itself. The mean trough and peak acyclovir concentrations and the daily area under the concentration-time curve acyclovir values at steady state were 2.5 and 8.4 micrograms/ml and 120 h micrograms/ml, respectively, after a dosage of 2,000 mg of valaciclovir four times daily. These values were approximately fivefold greater than those achieved with high dosages of oral acyclovir (800 mg, five times daily) and were not affected by continued use of medications necessary for management of advanced HIV disease. Thus, 2,000 mg of valaciclovir given orally four times daily should be evaluated for its potential efficacy in suppressing cytomegalovirus and other herpes group virus infections not optimally managed with current oral acyclovir therapy.
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PMID:Phase I trial of valaciclovir, the L-valyl ester of acyclovir, in patients with advanced human immunodeficiency virus disease. 797 85

Valaciclovir (BW256U87) is an L-valyl ester of acyclovir, which is extensively and almost completely converted to acyclovir. In healthy human volunteers, single valaciclovir doses of 100-1000 mg resulted in dose-proportional increases in acyclovir area under the curve (AUC). The 1,000 mg dose produced an acyclovir peak plasma concentration (Cmax) of 5-6 micrograms/ml, AUC6 of 19 hr. micrograms/ml, time to maximum plasma concentration (Tmax) of 1-2 hr, and half-life (T1/2) of 2.8 hr. Plasma valaciclovir peak levels were < 0.3 micrograms/ml, and the prodrug was undetectable after 3 hr. Multiple valaciclovir doses of 250-2,000 mg given four times daily for 10 days resulted in dose-proportional increases in acyclovir Cmax. There were less than proportional increases in the AUCs. No serious or unexpected adverse events or laboratory abnormalities were reported. In volunteers with advanced human immunodeficiency virus (HIV) disease (absolute CD4 lymphocyte count < 150 cells/microliters), acyclovir and valaciclovir pharmacokinetic results were nearly identical to those in healthy volunteers. At the 2 g dose administered four times daily, steady-state acyclovir Cmax = 8.4 micrograms/ml, Tmax = 2.0 hr, AUC6 = 30.5 hr. micrograms/ml, and T1/2 = 3.3 hr. Nausea, vomiting, diarrhoea, and abdominal pain were commonly reported; however, only one adverse event (diarrhoea) was causally linked to valaciclovir exposure. There were no renal or neurologic adverse events. Valaciclovir is well absorbed and is rapidly converted to acyclovir, resulting in three- to fourfold higher acyclovir levels than can be achieved with oral acyclovir, even in patients with advanced HIV disease. The safety profile is generally favourable, with no evidence of nephrotoxicity or neurotoxicity.
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PMID:Valaciclovir (BW256U87): the L-valyl ester of acyclovir. 824 83

Acyclovir is an antiviral agent that causes termination of viral DNA synthesis by inhibiting viral reverse transcriptase. Acyclovir is used therapeutically to treat herpes simplex, cytomegalovirus, Epstein-Barr, and varicella-Zoster. Although acyclovir is thought to be low in toxicity, it has caused an obstructive nephropathy from accumulation of crystals in renal tissue. A retrospective review (January 1995 through March 2000) was conducted of acyclovir toxicoses in dogs reported to the ASPCA National Animal Poison Control Center. Of 105 ingestions, 10 were considered cases of acyclovir toxicosis. The most common signs seen were vomiting, diarrhea, anorexia, and lethargy. Ingested dosages ranged from 40 to 2195 mg/kg bw. Polyuria and polydipsia were reported in I dog. In 6/10 cases, signs developed within 3 h of ingestion. Treatment included standard decontamination procedures, (ie induction of emesis, administration of activated charcoal), diuresis, and supportive care.
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PMID:Accidental ingestion of acyclovir in dogs: 105 reports. 1111 48

A neonate presenting to the emergency department can present a challenge to even the most experienced clinician. This article has focused on four deceiving and potentially devastating neonatal diseases. 1. Neonatal herpes is a potentially devastating illness without pathognomonic signs or symptoms. Early recognition and therapy can reduce mortality markedly. Although no specific sign or symptom is diagnostic,the diagnosis should be strongly considered in the presence of HSV risk factors, atypical sepsis, unexplained acute hepatitis, or focal seizure activity. Acyclovir therapy should be initiated before viral dissemination or significant CNS replication occurs. 2. Pertussis is a disease in which infants are at greatest risk of death or severe complication. Neonatal pertussis often presents in an atypical manner, lacking the classic signs and symptoms such as the "whoop."More common signs and symptoms include cough, feeding difficulty,low-grade fever, emesis, increasing respiratory distress, apnea, cyanosis,and seizures. Management should include hospitalization, supportive care, and antibiotics. 3. Congenital heart defects, particularly ductal-dependent lesions, may have an initial asymptomatic period that culminates in a rapidly progressive and fatal course. A neonate with CHD presents with shock refractory to volume resuscitation or pressor support. Resuscitative efforts are ineffective unless PGE, is administered. 4. Inborn errors of metabolism often are unsuspected because of their protean and heterogeneous nature. Signs and symptoms are subtle,are nonspecific, and often mimic other, more common diseases.An elevated index of suspicion, along with application and correct interpretation of a select few laboratory tests, is the key to making a diagnosis. Therapy is relatively straightforward and focused on resuscitation followed by prevention of catabolism and correction of specifically identified abnormalities. Although these disorders are relatively uncommon, prompt diagnosis and therapy can lead to a decrease in morbidity and mortality. The key is to maintain a high index of suspicion.
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PMID:Unsuspected neonatal killers in emergency medicine. 1547 77

Postherpetic neuralgia (PHN) is a serious complication of herpes zoster that has a predilection for older individuals. PHN is often associated with significant morbidity, and it can cause insomnia, fatigue, depression and interference with daily activities in affected individuals. Treatment for PHN is initiated with antivirals during the acute herpes zoster outbreak. Acyclovir (Zoviraxr, GlaxoSmithKline), valacyclovir (Valtrex, GlaxoSmithKline) or famciclovir (Famvir, Novartis) can be used to treat herpes zoster, and all three have been shown to reduce the duration of the herpetic rash and zoster-associated pain. These antivirals are most effective when used within the first 72 hours of the onset of the rash. Side-effects of these antivirals are low and include nausea, vomiting, abdominal pain and headache. Other treatment options for PHN include topical analgesics, opioid analgesics, tricyclic antidepressants and gabapentin. Because of the complexity of PHN, most patients require a combination of treatment modalities for adequate pain relief.
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PMID:Treatment of postherpetic neuralgia. 1555 Sep 90

Herpes simplex encephalitis (HSE) is a rare complication of neurosurgical procedures but must be considered in early deterioration of the postoperative patient. This is the first report of HSE following spinal cord tumor resection. A 65-year-old woman had C2-C5 laminectomy for subtotal resection of intramedullary ependymoma. Six days postoperatively she developed fever, vomiting and rapid decline in mental status. Brain MRI revealed enhancement of left insular cortex. Polymerase chain reaction on cerebrospinal fluid (CSF) identified herpes simplex virus type 1 (HSV-1) as the causal agent. Twenty-one days of acyclovir led to improvement. Three subsequent admissions to neurological intensive care unit were required for deterioration in mental status, including pneumonia, hydrocephalus and deep vein thromboses. Ventriculoperitoneal shunt (VPS), tracheotomy, percutaneous intravenous central catheter (PICC) line and percutaneous endoscopic gastrostomy (PEG) were placed. She was discharged to skilled nursing home care. Acyclovir is effective therapy against HSV, though outcomes may be poor even in optimally treated cases. Empiric treatment must be started even in the absence of serologic evidence of HSV infection if suspicion for HSE is high.
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PMID:Herpes simplex encephalitis following spinal ependymoma resection: case report and literature review. 2094 25

Acyclovir is used for its potent antiviral properties for the mucocutaneous herpes, herpes zoster, herpes encephalitis, and genital herpes simplex. The drug has a very wide distribution involving almost every organ of the body, with excretion into the urine. Urine analysis, kidney function, liver function, and complete blood counts are some of the monitoring parameters. The active triphosphate form of the drug inhibits DNA synthesis and viral replication by competing with deoxyguanosine triphosphate for viral DNA polymerase and being incorporated into viral DNA. Because the drug is only absorbed by the cells that are virus infected, acyclovir has minimal side effects at therapeutic doses. However, at high intravenous infusions, severe central nervous system (malaise), gastrointestinal (nausea/vomiting), renal (elevated blood urea nitrogen/creatinine), hepatic (elevated liver enzymes), and skin dyscrasias have been found to occur. There have been few case reports of bone marrow suppression and only one case report so far of acyclovir-related isolated thrombocytopenia. Whether there is any further association between acyclovir and thrombotic thrombocytopenic purpura/hemolytic uremic syndrome is the next dilemma if such an association is established. Here, the authors present a case report of a 58-year-old man with acquired immune deficiency syndrome on highly active antiretroviral therapy who went into severe thrombocytopenia on starting acyclovir.
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PMID:A rare case of acyclovir-induced thrombocytopenia. 2334 9

Herpes simplex virus (HSV) is the most common cause of non-epidemic, sporadic, acute focal encephalitis in the United States. Inflammation of the vasculature makes them friable and susceptible to hemorrhage. Massive hemorrhage, though rare, can present in a delayed fashion after initiation of acyclovir and often requires surgical intervention. We report a unique case of delayed temporal lobe hemorrhage after initiation of acyclovir in an immunocompetent patient, specifically for its presentation, virology, and surgical management. A 40-year-old left-handed Caucasian female with chronic headaches, along with a 20-pack-year smoking history, presented to an outside facility with one week of diffuse, generalized headache, fever, nausea, and vomiting. Initial cranial imaging was negative for hemorrhage. Cerebrospinal fluid (CSF) studies showed a lymphocytic pleocytosis with elevated protein, along with polymerase chain reaction (PCR) positive staining for HSV, establishing the diagnosis of HSV-2 encephalitis, which is less common in adults. Acyclovir was initiated and one week later while still hospitalized, the patient developed acute altered mental status with cranial imaging showing a large right temporal lobe hemorrhage with significant midline shift. She was transferred to our facility for surgical intervention. Computed tomography angiography (CTA) was negative for any underlying vascular lesion. She was taken to the operating room for a decompressive unilateral (right) hemicraniectomy and temporal lobectomy. She had no postoperative complications and completed a three-week course of acyclovir. She was discharged to acute rehab with plans to return at a later date for cranioplasty. Intracerebral hemorrhage is an uncommon, although possible sequela, of herpes encephalitis. Despite initiation of early antiviral therapy, close monitoring is warranted, given the pathophysiology of the vasculature. Any decline in the neurological exam and/or increasing symptomatology of increased intracranial pressure mandates immediate cranial imaging to evaluate for possible hemorrhage. Emergent surgical intervention is warranted with large temporal lobe hemorrhages.
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PMID:Delayed Temporal Lobe Hemorrhage After Initiation of Acyclovir in an Immunocompetent Patient with Herpes Simplex Virus-2 Encephalitis: A Case Report. 2819 84


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