Margaret M. McCarron

Clinical Pharmacy: Case Studies: Case Number 25 Gentamicin Therapy

This series of case studies has been prepared by the faculty of the Department of Clinical Education and Services at U.S.C. School of Pharmacy as a continuing education course for pharmacists. The cases are meant to be studied in sequence; concepts and laboratory test evaluations presented in one case will be used in subsequent cases. All normal laboratory test values will be those used at the Los Angeles County/U.S.C. Medical Center; values may differ at other hospitals depending on the method used. Medical material is presented to give the pharmacist an understanding of the case, it is not meant to teach the pharmacist diagnosis. The cases have been altered for teaching purposes so that they do not represent actual cases.

Acute phencyclidine intoxication: clinical patterns, complications, and treatment.

We describe four major and five minor clinical patterns of acute phencyclidine (PCP) intoxication and give the incidence of findings in each pattern. Major patterns were acute brain syndrome (248 cases; 24.8%), toxic psychosis (166 cases; 16.6%), catatonic syndrome (117 cases; 11.7%), and coma (106 cases; 10.6%). Minor patterns included lethargy or stupor (38 cases; 3.8%), and combinations of bizarre behavior, violence, agitation, and euphoria in patients who were alert and oriented (325 cases; 32.5%). Patients with major patterns of PCP toxicity usually required hospitalization and accounted for most complications. In general, patients with minor patterns had mild intoxication and did not require hospitalization except for the treatment of injuries or autonomic effects of PCP. Various types of injuries occurred in 16%, and aspiration pneumonia occurred in 1.0% of all cases. There were 22 cases of rhabdomyolysis (2.2%), with three patients requiring dialysis for renal failure. One patient who had been comatose from PCP died suddenly. A fresh pulmonary embolism was found at autopsy.

Castor bean intoxication

We report the cases of a child who ingested two or more castor beans and two adults who each ingested four beans. All three patients developed severe gastroenteritis and recovered without sequelae after receiving IV fluids. The literature contains reports of 424 cases of castor bean intoxication. Symptoms of intoxication include acute gastroenteritis, fluid and electrolyte depletion, gastrointestinal bleeding, hemolysis, and hypoglycemia. Delayed cytotoxicity has not been reported. Of the 424 patients, 14 died (mortality rates: 8.1% of untreated and 0.4% of treated). Deaths were due to hypovolemic shock. Recommended treatment for asymptomatic patients who have chewed one or more raw beans is emergency department evaluation, gastric decontamination, administration of activated charcoal, observation until four to six hours after ingestion, and discharge instructions to return if symptoms develop. After decontamination and activated charcoal, symptomatic patients require hospitalization for treatment with IV fluids, supportive care, and monitoring for hypoglycemia, hemolysis, and complications of hypovolemia. Monitoring for delayed cytotoxicity is unnecessary. Castor beans and their dust are highly allergenic and may cause anaphylaxis.

Rhabdomyolysis with and without Acute Renal Failure in Patients with Phencyclidine Intoxication

Rhabdomyolysis occurred in 25 of 1,000 patients (2.5%) with phencyclidine (PCP) intoxication. 10 of these 25 patients (40%) developed acute renal failure and another 7 had mild impairment in renal function. Marked hyperuricemia was present in all 17 patients, and marked hyperphosphatemia and hypocalcemia were noted in the 10 patients with acute renal failure; 3 of the latter developed hypercalcemia during the diuretic phase of the illness. Fever, tachycardia and hypertension were frequent findings among the 25 patients with rhabdomyolysis and all had leukocytosis. The data show that rhabdomyolysis with and without acute renal failure is not infrequent among abusers of PCP.

Heroin body packers

Fourteen body packers carrying 2-112 heroin packages are reported. Nine people swallowed the packets, and five inserted them rectally. The ingested packages were large and radio-opaque; they consisted of hard lumps of concentrated heroin usually covered with glove latex, white adhesive tape, and a toy balloon. There were two complications in the 14 patients. One patient developed a bowel obstruction; at laparotomy 8 packages were found in the stomach and 27 at the ileo-cecal valve. Another patient, with heroin wrapped only with black electricians tape and no latex inner or outer wrappings, developed heroin intoxication, noncardiogenic pulmonary edema, and a bowel obstruction. Eighteen packages were surgically removed from his stomach and 26 from his bowel. We recommend bisacodyl suppositories, activated charcoal mixed with a 3% sodium sulfate cathartic, and phosphosoda enemas for package removal; close observation for heroin toxicity or bowel obstruction; and surgical intervention for continuing toxicity, retention of packages in the stomach, or bowel obstruction.

Acute Yellow Phosphorus Poisoning from Pesticide Pastes

Ten cases of ingestion of yellow phosphorus rat poison, including four cases that occurred during the past 3 years, are reported. Comparison of these cases with 82 others from the literature showed that ingestion of yellow phosphorus paste often results in clinical findings that are different from those described for acute yellow phosphorus poisoning in current toxicology texts. The time lag between swallowing of the poison and onset of symptoms varied from a few minutes to 24 h. Garlic odor, mucosal burns, and phosphorescent vomitus or feces occurred in only a small percentage of cases. Diarrhea was not a presenting complaint. Initial symptoms were referable to the gastrointestinal tract, central nervous system, or both. Mortality rates were 23% for patients who had early symptoms of vomiting or abdominal pain; 73% for those where the first manifestation of intoxication was restlessness, irritability, drowsiness, stupor, or coma; and 47% for patients who had a combination of these GI and CNS symptoms initially. Applying standard diagnostic criteria for yellow phosphorus poisoning to patients who have consumed yellow phosphorus pastes may result in serious diagnostic errors.

PENTAZOCINE (TALWIN@) INTOXICATION: REPORT OF 57 CASES

Overdose of pentazocine (Talwin), an agonist/antagonist opioid analgesic, is relatively uncommon. Fifty-seven cases occurring over ten years are reported. Twenty-three patients (40%) had ingested only pentazocine and did not have the classic opioid toxidrome of CNS and respiratory depression with miosis. Most patients were awake, and no patient had a respiratory rate below 12/minute. Other findings included: grand mal seizures, hypertension, hypotonia, dysphoria, hallucinations, delusions, and agitation. Eleven of 23 patients received IV naloxone (0.4-2.4 mg), but only two showed improvement. Thirty-four patients (60%) had coingested pentazocine with one to five additional substances. Patients who had ingested pentazocine with alcohol, a sedative/hypnotic drug, or an antihistamine, showed increased toxicity, including apnea, deep coma, and recurrent seizures. One patient developed opioid pulmonary edema. One patient died. Three of five patients with coma and inadequate respirations responded to IV naloxone in doses of 0.4 to 1.2 mg.

Pine oil cleaner ingestion

We report the cases of 22 patients who were hospitalized for pine oil cleaner ingestion. The toxic manifestations most commonly observed were mucous membrane and gastrointestinal irritation. Ataxia, which did not occur in adults, was a frequent presenting sign of intoxication in children. Fifty-nine percent of patients who ingested only pine oil cleaner developed central nervous system depression, and three of these developed coma. Three of five children and three of 17 adults developed acute hydrocarbon pneumonitis. Unlike aspiration pneumonitis, which follows petroleum distillate ingestion, chemical pneumonitis from pine oil cleaner may occur from gastrointestinal absorption of pine oil and deposition in lung tissue. However, recovery from pneumonitis in our patients was typically rapid and complete. Only two adults developed secondary bacterial pneumonia; no patient died. Ingestion of pine oil cleaner was rarely life threatening; most patients needed only gastrointestinal decontamination and minimal supportive care.

Ammonium nitrate cold pack ingestion.

Disposable ammonium nitrate cold packs are widely used in emergency departments instead of ice bags. Five confused or suicidal patients who tore open a pack and ingested from 64 to 234 grams of ammonium nitrate in a single dose, and another patient who attempted to do so, are reported. It is known that chronic ingestion of 6 to 12 grams/day of ammonium nitrate may cause gastritis, acidosis, isosmotic diuresis, and nitrite toxicity manifesting as methemoglobinemia or vasodilatation. None of these patients developed severe toxicity, although three had symptoms of gastritis, three had slight methemoglobinemia, and two had mild hypotension. The product was removed from the stomach promptly in three of the five patients. None had pre-existing renal or intestinal dysfunction, which are known to enhance ammonium nitrate toxicity.

A system of inpatient drug monitoring.

THERE ABE DIFFEEENT TYPES of drug monitoring systems. These range from relatively uncomplicated drug profiles for individual patients to epidemiological studies in large population groups. Individual drug profiles are usually designed to enable the pharmacist to keep a record of all the drugs (prescription and OTC) that the patient is currently using and to obtain information about the patients known allergies, previous adverse drug reactions and idiosyncrasies to specific drugs. The pharmacist uses this profile in reviewing new prescriptions to detect inappropriate concurrent prescribing and to protect the patient from having a recurrence of allergy or adverse drug effects. Other profiles are designed to monitor specific patient therapy, such as long-term anticoagulant treatment in patients with cardiac valve replacement, or a variety of diseases in an outpatient population. The Boston Collaborative Study is an example of a sophisticated surveillance program in which a limited number of beds in nine different hospitals are closely monitored to record all significant medical events that occur to a patient during hospitalization, and to analyze those events by computer to provide quantitative data on