Treatment rationale for dogs poisoned with aldicarb (carbamate pesticide).

The treatment rationale for dogs poisoned by aldicarb is reviewed from a pharmacological perspective. The illegal use of aldicarb to maliciously poison dogs is a major problem in some parts of the world. In South Africa, it is probably the most common canine poisoning treated by companion animal veterinarians. Aldicarb poisoning is an emergency and veterinarians need to be able to diagnose it and start with effective treatment immediately to ensure a reasonable prognosis. Successful treatment depends on the timely use of an anti-muscarinic drug (e.g. atropine). Additional supportive treatment options, including fluid therapy, diphenhydramine, benzodiazepines and the prevention of further absorption (activated charcoal) should also be considered. Possible complications after treatment are also briefly discussed.

Toxicovigilance. I: A survey of acute poisonings in South Africa based on Tygerberg Poison Information Centre data.

BACKGROUND: The incidence and spectrum of acute poisonings in South Africa are unknown. Poisoning data can be derived from sources such as hospital admission records and poison information centre (PIC) records. OBJECTIVES: This study was conducted to examine the extent of the problem and to identify trends and toxicovigilance issues using PIC data. METHODS: A survey was conducted based on Tygerberg Poison Information Centre (TPIC) consultations over 1 year. TPIC consultation forms were analysed for patient demographics and causes of poisoning. RESULTS: The TPIC dealt with 4 771 consultations related to human exposures to poisonous substances. The study showed that accidental exposure was more common than intentional poisoning (65.2% v. 34.8%); that 55.8% of cases were adults, of which 57.6% were females; and that 61.4% of adult cases were intentional exposures, and of these 64.3% were females. There was a predominance of accidental exposures (98.8%) and a male predominance (59.7%) in children. Categories of poisoning exposures across all age groups were non-drug chemicals (52.7%), medicines (35.2%) and biological toxins (12.6%). Pesticides (34.8%), irritant/corrosive substances (27.7%) and volatile hydrocarbons (8.3%) were the most common classes of non-drug chemical exposures. Cholinesterase inhibitors (8.8%), anticoagulant rodenticides (7.1%) and pyrethroids (5.0%) were the most commonly ingested non-drug chemicals. Aldicarb and amitraz poisoning were identified as toxicovigilance targets. Analgesics (26.1%) were the most common class of medicine-related exposure, and paracetamol (15.8%), benzodiazepines (9.2%) and antihistamines (5.2%) were the most common medicine-related exposures. CONCLUSION: The study provided information on evolving trends and identified toxicovigilance targets and the need for continuing toxicology education programmes.

Toxicovigilance. II: A survey of the spectrum of acute poisoning and current practices in the initial management of poisoning cases admitted to South African hospitals.

BACKGROUND: Initial management of acute poisoning in South African (SA) hospitals such as gastric decontamination and use of antidotes has not been evaluated relevant to current international guidelines. OBJECTIVES: The objective of this study was to conduct a toxicovigilance survey of SA hospital admissions to assess the spectrum of acute poisonings, current practices in gastric decontamination, and use of antidotes in the management of acute poisoning. METHODS: A survey was undertaken based on acute poisoning admissions to Tygerberg Academic Hospital (TAH) as well as hospital-based poisoning consultations with the Tygerberg Poison Information Centre (TPIC) over 1 year to investigate trends in admissions and the initial management of hospital admissions for acute poisoning. TAH admission details and TPIC consultation forms for hospital-based cases were analysed for patient demographics, causes of poisoning, gastric decontamination measures and use of antidotes. RESULTS: There were 662 admissions to TAH and 2 459 hospital-based TPIC consultations. Paracetamol and cholinesterase inhibitors were the most common exposures in both studies. Gastric decontamination measures were employed at TAH in 47.7% of cases and in 5.3% of hospital cases reported to the TPIC. Of these, 67.4% in the TAH study and 26.1% in the TPIC study did not comply with international guidelines. N-acetylcysteine was administered inappropriately in 22.1% of the paracetamol poisoning cases at TAH and in 1.6% in the TPIC study. Atropine was administered unnecessarily in 12 of 30 TPIC cases. CONCLUSION: This study has identified the need for directed training on gastric decontamination measures and use of antidotes and, combined with the previous study, has identified national trends in poisoning.

Seasonal variation in uterotonic activity of Rhoicissus tridentata extracts.

BACKGROUND: Rhoicissus tridentata lignotubers are widely used in southern African traditional pregnancy-related remedies. OBJECTIVES: To determine the seasonal variation in contractile activity of extracts from different parts of the plant. METHODS: Isolated rat uterus tissue was used to compare the contractile activity of crude aqueous extracts of R. tridentata made from plant material harvested every 3 months over a period of 2 years. RESULTS AND CONCLUSIONS: The activity of the plant extracts from plants harvested in summer and autumn were 4-5-fold higher than extracts from plants harvested in winter or spring. The tubers stimulated the greatest degree of contractions, followed by the stems, roots and leaves. These results highlight the need to standardise the timing of harvesting R. tridentata.