Botanical Name
Nicotiana tabacum Linn.
Synonyms
No documentation
Family
Solanaceae
Vernacular Names
| Malaysia | Tembakau |
| English | Tobacco |
Description
Nicotiana tabacum is a member of the Solanaceae family. It is a small annual (some varieties are perennials) which can grow up to 3 m tall. The leaves are ovate to lanceolate, alrernate, spiralling around the stem. They can measure between 0.6 to 1 m long and half as wide. The flowers are tubular, colour ranges from white to cream to pink to carmine red, growing in terminal clusters. The individual flower is measure about 3.5 to 5 cm long. The fruits are oval to elliptical capsules with numerous small brown seeds (0.5 mm). [5]
Distribution
N. tabacum is native of South America, but since has been cultivated in many regions of the world for the leaves which is used in the popular habit of cigarette smoking. [5]
Plant Use
Leaves are smoked, chewed or snuffed and it is addictive. In its native land it had been used medicinally. The leaves are considered antispasmodic, diuretic, expectorant, irritant, narcotic and sedative. It is useful for the treatment of rheumatic swellings, skin diseases and even scorpion stings. It can relieve painful haemorrhoids and eye infections. [1] [2] [3] [4] [5] [6]
Toxic Parts
The whole plant is poisonous especially the leaves and fruits. [1] [2] [3]
Toxin
Nicotine and related compounds anabasine and nornicotine are the main toxic alkaloid found in the plant. The leaves and fruits is where most of these toxin lies (2 – 3 % nicotine) with lesser amounts in the roots, flowers and stems. The primary action is activation and then blockade of nicotinic acetylcholine receptors. This activation in the cortex, thalamus, inter-peduncular nucleus accounts for the coma and seizures seen in toxic doses of nicotine. The activation of the receptors in autonomic ganglia produces various effects on the sympathetic and parasympathetic nervous system. These effects include nausea, vomiting, diarrhoea, bradycardia, tachycardia and miosis. They also act as depolarizing neuromuscular blocking agent producing fasciculations and paralysis. [1] [2]
Risk Management
The indiscriminate disposal of cigarette buds by adults pose a danger of probable poisoning to curious infants and toddlers. There have been reported cases of deaths from consumption of remnants of tobacco in cigarette buds by toddlers throughout the world. Workers in tobacco plantation should wear protective gloves to prevent the occurrence of green tobacco sickness. [1] [2]
Clinical Findings
Nicotine or its related compounds can lead to any or all of the listed symptoms below:
Mucurinic – Salivation, lacrimation, urination, gastrointestinal cramping. emesis, myosis, bronchspasm and bradycardia.
Nicotinic – Weakness, fasciculations, paralysis, tachycardia, coma and seizure.
Symptoms of mild nicotine intoxication include salivation, nausea, vomiting, loss of equilibrium and sensory disturbances. There is also stimulation of peristalsis of the gastrointestinal tract with frequent and vigorous evacuations of the bowels being the consequence.
In acute intoxications there would be convulsions, tachycardia and increase in blood pressure and this is followed by curare-type paralysis of the muscles which leads to death from respiratory failure. Very large oral dose is fatal within seconds and any lethal dose will produce death in minutes.
Green tobacco sickness commonly affects workers handling leaves where nicotine absorbed through the skin. Symptoms include nausea, vomiting, diarrhoea, diaphoresis and weakness that usually resolve with symptomatic treatment. [1] [2]
Management
The management of tobacco poisoning is essentially symptomatic and supportive with special attention to ventilation and monitoring of vital signs.
Acute Poisoning
Emergency Procedure
1. Skin contamination requires thorough washing with copious soap and water with vigorous scrubbing.
2. Give activated charcoal to adsorb any remaining nicotine. The usual dose is 30 – 100g in adults and 15 – 30 g in children ( 1 – 2g/kg in infant)
3. Gastric Lavage – indicated if performed immediately after ingestion or in comatose patient or those at risk of convulsing. It is best to have the patient in the Trendelenburg and left lateral decubitus or with cuffed endotracheal intubation in order to protect the airways. Use tap water containing activated charcoal.
4. Artificial respiration with oxygen should be initiated when available.
Specific Drugs and Antidotes
1. Mecamylamine is the specific antidote to nicotine.
2. Atropine sulphate (adult 0.4 – 2 mg; child 0.01mg/kg, not to exceed 0.4 mg per dose) im or iv and repeated every 3 – 8 minutes until signs of parasympathetic toxicity is controlled. Atropine can be continued to control symptoms. Ensure proper oxygenation to avoid arrhythmias associated with hypoxia. Interruption of atropine therapy may result in death due to pulmonary oedema or respiratoty failure.
3. Phentolamine 1 – 5 mg i.m. or i.v. to control signs of sympathetic hyperactivity.
General Measures
1. Control of convulsions by administering Diazepam i.v bolus ( adult 5 – 10 mg initially to be repeated every 15 minutes if necessary; child 0.25 – 0.4 mg/kg dose up to 10mg/dose) or Lorazepam i.v. bolus (adult, 4 – 8 mg; child, 0.05 – 0.1mg/kg)
2. Monitor ECG and vital signs carefully
Caution: Antacids is an absolute contraindication as nicotine is known to be better absorbed in alkaline medium.
NB: Complete recovery can be expected if victim survives more than 4 hours. [3] [4]
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References
1. Nellis DW.Poisonous Plants and Animals of Florida and the Caribbean, Pineapple Press, Sarasota, 1997, pg. 240
2. Holstege C, Neer T, Saathoff G, Furbee B. Criminal Poisoning: Clinical and Forensic Perspectives, Jones & Barlett Publishers, Sudbury, 2010, pg. 119 – 122
3. Nelson LS, Shih RD, Ballick MJ. Handbook of Poisonous and Injurious Plants, Springer, New York 2007 pg. 224 – 226
4. Available from http://www.prn.usm.my/old_website/mainsite/bulletin/1995/prn2.html. Accessed on 3rd February 2013.
5. Available from http://eol.org/pages/581050/overview. Accessed on 4th February 2013
6. Odugbemi T., A Textbook of Medicinal Plants of Nigeria University of Lagos Press, Akoka 2008 pg. 308
