Hypertensive crisis and myocardial infarction following massive clonidine overdose

OBJECTIVE

To describe a patient who experienced a hypertensive crisis and myocardial infarction following a massive dose of parenteral clonidine.

CASE SUMMARY

A 62-year-old white woman with stage 3 breast cancer metastatic to the spine and a history of hypertension received a combined injection of hydromorphone 48.3 mg and clonidine 12.24 mg subcutaneously in an attempt to refill an implanted epidural infusion pump. She promptly developed mental deterioration, blurred vision, worsening respiration, tachycardia, and hypertension. She was immediately treated with naloxone, but subsequently experienced hypertensive urgency, a short-duration tonic-clonic seizure, and an anteroseptal myocardial infarction. Cardiac catheterization showed no arteriolar narrowing or blockage, but an anterior infarct was confirmed.

DISCUSSION

Clonidine is a commonly used alpha-adrenergic agonist. At usual oral doses of 0.2-2 mg/d, it acts centrally to produce hypotensive effects; at doses >7 mg/d, it acts peripherally to stimulate alpha1- and alpha2-adrenergic receptors, leading to vasoconstriction and increased blood pressure. These effects are not easy to control by standard medical therapies and can cause significant morbidity.

CONCLUSIONS

Clonidine, although a safe medication with usual dosages, must be used with caution when given in injectable form. An overdose of this alpha-adrenoreceptor agonist can produce significant vasospasm and hypertensive emergency. Drugs used to treat overdose, such as naloxone, can potentiate clonidine's adverse effects, leading to further morbidity.

Payment deferred: strychnine poisoning in Nicaragua 65 years ago

BACKGROUND

In 1933 in Leon, Nicaragua, a 22-year-old woman died after an acute convulsive illness in which she experienced trismus, opisthotonos, and hyperpyrexia. Three years later her husband, Oliverio Castaneda, was convicted of her murder and that of 2 other people in the same city.

METHODS

We went to Nicaragua to investigate documents involved with that case and evaluate whether the verdict of murder by strychnine was substantiated by the data. We present the results of the investigation and provide information about the practice of medicine, pharmacy, and toxicology early in this century.

RESULTS

The clinical picture in all 3 cases suggests strychnine poisoning. The clinical, toxicological, and circumstantial evidence is strong and implicates Castaneda as a murderer and strychnine as the weapon.

CONCLUSION

We conclude that Oliverio Castaneda was the probable perpetrator of three 1933 strychnine murders in Leon and that he may have previously used strychnine to kill others in Nicaragua and neighboring countries.

Effect of glycine on valproate toxicity in rat hepatocytes

The interaction between the amino acid glycine and valproate (VPA), an antiepileptic drug (AED) that occasionally causes hepatotoxicity, was studied in rat hepatocytes in monolayer culture. Valproate caused a dose-dependent increase in leakage of lactic acid dehydrogenase (LDH), and glycine prevented this toxic response. L-Carnitine, L-alanine, and L-cysteine did not protect hepatocytes from VPA. Glycine also partially antagonized inhibition of fatty acid beta-oxidation by VPA, as estimated by the generation of acid-soluble products from [14C]palmitic acid. These results are consistent with the hypothesis that glycine prevents VPA toxicity by removing acyl-CoA esters, which accumulate during VPA exposure and interfere with fatty acid beta-oxidation. Glycine, however, also antagonized the toxic effects of acetaminophen on hepatocytes, although at higher concentrations than required to protect hepatocytes from VPA. Because the mechanism of toxicity of acetaminophen probably is different from that of VPA, a nonspecific cytoprotective effect may contribute to glycine antagonism of valproate toxicity. Our results emphasize the importance of glycine in protecting hepatocytes from noxious insult in general as well as from VPA in particular.

Principles of irrational drug therapy

Drugs are extensively used in medicine when they are unlikely to produce a benefit to the patient. In most instances this does no apparent harm to the patient but sometimes (for example, the extensive use of thorotrast) the results are tragic. Even when the patient is not injured, overuse of medicines is an undesirable and money-wasting behavioral pattern. Several factors relating to the social process of drug use which encourage overprescribing are discussed and the Principles of Irrational Drug Therapy are derived. These principles are presented as negative role models for the use of medicines in developing countries.

Endocrine and clinical effects of leuprolide in prostatic cancer

Twenty-nine subjects with metastatic carcinoma of the prostate received daily subcutaneous injections of leuprolide, a luteinizing hormone-releasing hormone analog. After transient gonadotropin and androgen stimulation, leuprolide induced long-term suppression of serum testosterone and gonadotropins production. In 25 subjects there was objective disease stabilization or tumor regression. Eleven subjects subsequently relapsed (median = 10 mo) after initiation of treatment. Except for vasomotor hot flashes, leuprolide appears to be well tolerated by patients with advanced prostatic cancer.

Cholinergic potentiation of neuroleptic effects in the nucleus accumbens

The CNS cholinergic agonist spiro-(1-methyl-4-piperidyl)-N-ethyl-succinimide (RS-86) potentiated the ability of typical neuroleptics to inhibit the hyperactivity induced by direct injection of dopamine to the nucleus accumbens of pargyline-pretreated rats. RS-86 did not augment the anti-dopamine actions of clozapine, an atypical neuroleptic. Tricyclic antidepressants alone or in combination with RS-86 had no effect on the hyperactivity. The antidepressants displayed moderate inhibition of dopamine-sensitive adenylate cyclase in homogenates of the limbic system relative to the neuroleptics.

Four-year treatment of patients with parkinsonism using amantadine alone or with levodopa

Half of 94 parkinsonian patients improved on amantadine therapy during acute double-blind trials. In a four-year follow-up, amantadine given alone or added to a stable dose of levodopa had its greatest effect in the first month and helped few patients after six months. Levodopa either alone or added to a stable dose of amantadine had a beneficial effect lasting three years or more. The side-effects of edema and livido reticularis occurred twice as often in women. Confusion and hallucinations appeared sooner on a regimen of 300 mg of amantadine a day, but the ultimate incidence was the same on 200 mg a day. Withdrawal effects from amantadine are no less frequent or serious than from other antiparkinson medications and are not evidence that amantadine is still helping the patient. Considering the years of exposure, the morbidity and mortality do not indicate any risks peculiar to amantadine. Our mortality in all groups combined was 2.4 times that of the age- and sex-matched United States population.

Potentiation of tricyclic antidepressant toxicity by physostigmine in mice

Subtoxic doses of physostigmine have been found to potentiate the convulsive toxicity and lethality of amitriptyline and imipramine in CD1 and B6A mice. Neostigmine failed to potentiate the toxicity and lethality of imipramine. Physostigmine tended to protect mice against atropine-induced lethality. These data suggest the site of toxicity of this drug-drug interaction between the tricyclic antidepressants and physostigmine may be occurring in the CNS through a mechanism distinct from the anticholinergic actions of the antidepressants.