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Home , Cinchonism, Decongestant

.COMM January 2006

Volume 1, Issue 1

Inside This Issue Welcome to the first issue of the Poisoning.Comm! Poisoning.Comm is a new Features: Small Doses, Big Problems — online publication by the Department of Health. That Are Highly It is dedicated to raising the awareness Dangerous To A Toddler 2 amongst local healthcare professionals on poisoning. It will be published quarterly. The “Look-alike / Sound-alike”: theme of this issue is poisoning in children. Do Arising From Confusions – vs. 3 you know what medications can cause fatality to children on accidental poisoning? Is Quinine

Case Report: the same as Quinidine? What to do if a baby is Nasal Decongestant Poisoning poisoned with a nose drops? We invite you to To A Nine-month Old Baby 4 read on and find out!

Dr TH Leung Toxicological Surveillance 5 Deputy Director of Health

Hong Kong Information Centre

The Hong Kong Poisons Information Centre (HKPIC), jointly established by the Department of Health, Hospital Authority, and the and Poisons Information Bureau of The Chinese University of Hong Kong, has commenced operation since July 2005. Manned by medical personnel specially trained in clinical , the HKPIC provides health care professionals with information and advice on the diagnosis and management of acute and chronic poisoning by drugs, chemicals, household products, health products, herbal medicines or natural .

In its initial stage of operation, the HKPIC provides urgent consultation service by phone during the operating hours, while non-urgent consultations and enquiries can be made by facsimile or E-mails at any time.

The hours of operation and contact details of the HKPIC are as follows:

Operating hours 9 am to 9 pm Daily Telephone 2635 1111 Facsimile 3513 5649 E-mail [email protected]

Please feel free to contact Dr FL LAU, Director of the HKPIC at 35135089 for matters related to the HKPIC.

1 Small Doses, Big Problems - Medications That Are Highly Dangerous To A Toddler Features Professor Thomas Y.K. Chan, Director of Centre for Food and Safety, Faculty of Medicine, The Chinese University of Hong Kong

In accidental poisoning in children, the 2-year-olds are the most commonly involved. Exposure to poisons occurs predominately at home. Product accessibility is by far the most important factor. Easily visible or accessible storage locations such as the floor, table top, fridge, kitchen cupboard and handbag increase the risk of accidental poisoning. Medications should always be safely packed and stored. The giving of precautionary advice to parents should also help reduce the incidence of childhood poisoning. The list of medications that can cause fatalities in toddlers with 1-2 dose units includes antimalarials, calcium channel blockers, tricyclic , , narcotic , , sulphonylureas and topical analgesics (see Table below). Physicians should be familiar with this list of medications which are extremely dangerous for toddlers, as well as the management of such poisoning.

Table - Medications that can be fatal to a 10 kg toddler upon ingestion of a small dose.

Pharmacological classification or Major toxic effects Indication

Chloroquine Cardiac , seizures, Antimalarial Hydroxychloroquine coma, respiratory arrest

Antimalarial Cardiac arrhythmias, seizures, Quinine coma, hypoglycaemia, Nocturnal leg cramping visual damage

Anti-arrhythmic Cardiac arrhythmias, seizures, Quinidine (d-isomer of quinine) Antimalarial coma

Verapamil , bradycardia, heart Diltiazem block, cerebral hypoperfusion Amitriptyline Cardiac arrhythmias, respiratory Desipramine Tricyclic failure, coma, anticholinergic effects Imipramine

Chlorpromazine Cardiac arrhythmias, seizures, Thioridazine dystonic reactions Codeine Methadone Narcotic Coma, respiratory depression Morphine Cardiac arrhythmias, seizures, Theophylline profound hypokalemia Chlorpropamide Long-acting sulphonylurea Prolonged hypoglycaemia Glibenclamide Rapid-onset with both Camphor Liniment for muscle aches excitatory and actions

Rapid-onset, severe salicylate Methyl salicylate Topical analgesic poisoning

"Red Flower Oil" Rapid-onset, severe salicylate Topical analgesic (contains methyl salicylate) poisoning

2 Toxicity Arising From Confusions – Quinine vs. Quinidine “Look-alike / Sound-alike” Ms. Teresa Ngan, Senior Pharmacist, Hospital Authority Mr. Edmund Cheung, Pharmacist, Hospital Authority

Toxicity of drugs does not always arise from overdosing, but Quin-id-ine (1,2,3) also from occasions when a wrong drug is erroneously prescribed or dispensed to a patient. Many errors are caused Indications: by confusions dealing with look-alike and sound-alike drugs. ★ maintenance of sinus rhythm, Quinine and Quinidine are look-alike (when written) and in patients with atrial fibrillation sound-alike (when pronounced) medications. When we ★ prevention of recurrence of mistakenly add an “id” to Quinine, it becomes Quin-id-ine. ventricular tachycardia or Despite the similarity in their names and pronunciations, their ventricular fibrillation usages are entirely different. Quinine is commonly used for ★ Treatment of when malaria and leg cramping, and Quin-id-ine is an anti- quinine is not immediately available arrhythmic agent. Erroneous substitution by one or the other (4) in prescribing or dispensing can lead to not just medication errors, but also serious . Clinical features in overdose:

★ Cardiac effects: bradycardia, Both Quinine and Quin-id-ine are highly toxic compounds. prolongation of the PR interval, They can cause adverse effects in susceptible patients even lengthening of the QT interval, in therapeutic doses. For instance, if a prescriber mistakenly widening of the QRS with development of an idioventricular prescribes “Quin-id-ine bisulphate 250mg to be taken 3 rhythm. Ventricular fibrillation may sometimes follow. times daily” instead of “Quinine bisulphate 300mg at ★ pressure decreases progressively and hypo- bedtime” for leg to a patient with heart failure or heart block, this can result in life-threatening consequence. kalemia may occur. The summaries of the toxicities of Quinine and Quin-id-ine ★ Syncope and convulsion. are appended below as quick reference. Commercial products: Quinine (1,2,3) ★ Quin-id-ine bisulphate 250mg in sustained release form

Toxic dose: Indications: ★ Adults: 3 – 4gm (40 – 50 mg/kg) ★ -resistant and (Doses over 1gm may cause symptoms, especially in multidrug-resistant falciparum chronic heart failure. Concurrent use of beta-blockers malaria and tricyclic antidepressants may precipitate Quin-id-ine ★ nocturnal leg cramps (night toxicity.) cramps) ★ Children: 50 – 100 mg/kg

Clinical features in overdose: Management in Quinine and Quin-id-ine Overdose ★ Cinchonism: , ★ Supportive and symptomatic measures including , , deafness, maintenance of the airway, breathing and circulatory status headache, vasodilatation and of the patient and observation for dysrhythmia. Clinical slightly disturbed vision. assessment for signs of seizure activity is also important. ★ Quinine blindness (amblyopia) ★ Gastrointestinal decontamination with activated charcoal appears in 20 – 40% of acute overdoses with a mean time of should be instituted to all patients in overdose. Repeated onset of 9 hours post-ingestion.(2) doses may increase clearance of the drugs.(1,2) ★ CNS depression, coma and convulsions. ★ No is available for Quinine and Quin-id-ine. ★ In general, the cardiac effects of Quinine in overdose are less severe than those of Quin-id-ine (its optical isomer). References 1. International Programme on Chemical Safety: INCHEM Commercial products: – Poisons Information Monographs on Quinine & Quinidine ★ Quinine sulphate 200mg and Quinine bisulphate 300mg 2. Whyte IM. Ch94: Antimalarial agents. In: Dart RC et al (Eds). Medical Toxicology. 3rd edition. Philadelphia: Lippin- Toxic dose: cott Williams and Wilkins; 2004. p466-74 ★ Adults: 2.5 – 4gm 3. Drugs & Therapy Perspectives 2004: Volume ★ Children: >25mg/kg 20, Number 12 (In fact, Quinine is one of the very few drugs that can cause 4. Martindale: The complete drug reference 34th ed. The potential fatality for a 10kg toddler on ingestion of only Pharmaceutical Press “one dose” of commercially available product.(2) Thus, parents are reminded to store this drug in child-proof containers and keep away from the reach of their children when they have elders at home taking Quinine bisulphate 300mg at bedtime for night cramps.)

3 Nasal Decongestant Poisoning To A Nine-month Old Baby Case Report

Dr. M L Tse, Senior Medical Officer, Hong Kong Poisons Information Centre

A nine-month old baby became unarousable and The mainstay of treatment is supportive. Activated pale-looking shortly after he was administered a nasal charcoal may be considered if significant amount was decongestant at home. He was brought to the ingested and patient presented early.(2,3) Emergency Room immediately. Physical examination revealed a drowsy baby, not responding to verbal and Imidazoline nasal decongestants are commonly tactile stimuli, with some spontaneous movement of prescribed by doctors and are available over the four limbs and withdrawal on pain. Pupils were 2mm in counter. However, in view of its potential toxicity, its length and sluggishly reactive to light. The capillary use in children, especially those under 2 years old refill was delayed. He was clinically in a shock state. should be cautious. Carers should be informed of its His and pulse were 80/40mmHg and toxic effects. Use in infants needs close supervision. 70/min respectively. Electrocardiogram showed a sinus rhythm of 70/min, which was slow for his age, whereas Contra-indication of Imidazolines includes narrow QRS and QTc intervals were normal. Oxygen angle glaucoma. Prolonged use of more than 7 days is saturation and glucosestix were normal. not recommended. They should be used with cautions This baby was given oxygen and intravenous fluid in patients with cardiovascular diseases, , bolus. His clinical condition improved with better colour diabetes mellitus, thyroid diseases, enlarged prostate and capillary refill. He was then transferred to the and patients on monoamine oxidase inhibitors or paediatric intensive care unit for further care. tricyclic antidepressants.(4) Further history revealed that this baby suffered from upper symptoms and was treated by a Patients or their carers should exercise care on private doctor. Prescription included a bottle of . As illustrated in this case report, the drops containing . However, the baby’s nose drops were supplied in the form of a small plastic grandmother inadvertently put half a bottle of the nasal bottle of about 5-ml size. Accurate dose delivery drops (5mls) down the baby’s nostrils. Within fifteen cannot be guaranteed by the elderly carers due to poor minutes, the baby turned sick. dexterity. Prescribers should consider their patient’s This baby turned out to be fine after admission. No ability of accurate dosing with such device before further fluid bolus or pressor support was needed. He prescribing. regained full consciousness 4 hour after admission. References DISCUSSION 1. Registered pharmaceuticals in Hong Kong. De- Imidazoline and its derivatives are found in 142 partment of Health, The Government of HKSAR. registered pharmaceutical products in Hong Kong, www.psdh.gov.hk/pharmsearch Accessed on 19 Oct. mainly in the form of nose drops, nasal sprays or eye 2005 drops. Available ingredients are tetrahydrazoline, 2. RS Weisman, and decongestants. , oxymetazoline and .(1) In: Goldfrank’s Toxicological Emergencies, Sixth Ed. They are generally grouped as Imidazolines, Stamford, Connecticut: Appleton & Lange; 1998. a , which share similar p.608-12. therapeutic and adverse effect profiles. They act on 3. POISINDEX Imidazoline Decongestants. MICRO- alpha- receptors and were structurally MEDEX Healthcare series. 1974-2005 Thomson MI- related to clonidine. Overdosing with Imidazolines can CROMEDEX. cause central alpha-2-adrenergic stimulation. Children 4. DRUGDEX Evaluations. MICROMEDEX under 2 years of age are particularly susceptible. Healthcare series. 1974-2005 Thomson MICRO- Typical adverse effects include initial hypertension MEDEX followed by hypotension, hypothermia, respiratory depression, loss of consciousness and coma. Poisoned patients may have small pupils and may respond to naloxone but the effect is unpredictable.

4 Toxicological Surveillance

Figure 1: Age Distribution of Patients During the period from 1 July to 30 30 September 2005, 613 poisoned patients sought medical assistance at 25 the accident & emergency 20 departments of 6 acute regional hospitals (PMH, PWH, PYNEH, QMH, 15 TMH, & UCH) in Hong Kong. The 10 male to female ratio was 1: 1.3. Percentage (%) The age distribution of the patients is 5 shown in Figure 1. 0 0-4 5-9 10-14 15-24 25-34 35-44 45-54 55-64 65-74 >74 Majority (51%) of the Age range occurred at homes while only 5% occurred at workplaces, the rest of Figure 2: Nature of Poisoning the cases (44%) occurred in other places. Half of the cases were 50% suicidal in nature, accidents 40% accounted for 39% of the cases and 7% were related to recreational 30% activities (Figure 2). 20%

More than 60% of the cases % of patients 10% involved western medicines (e.g. paracetamol, benzodiazepines, 0% antidepressants, opioids etc). Suicidal Accidents Recreational Adverse Homicidal Therapeutic Insect stings and bites accounted for Activities Drug Errors 16% of the cases while environmental Reactions chemicals, Chinese medicines and household products (e.g. Figure 3: Poisoning Agents Involved disinfectants) accounted for 8%, 6% 16% 4% 1% 6% and 4% respectively (Figure 3). 8% 4% Two death cases were reported. The first death case involved an 80-year- old woman who committed suicide by concomitant ingestion of a household disinfectant and anti-hypertensives. 61% The other case involved a 27-year- Chinese Medicines Western Medicines old woman who committed suicide by Household Products Environmental Chemicals burning charcoal. Insect Stings & Bites Multiple Agents Others

Editorial Team: Dr TH Leung, Prof. Thomas Chan, Dr Albert Chan, Dr FL Lau, Dr Tony Mak, Dr Sammy Ng, Dr Henry Ng, Dr ML Tse, Ms Teresa Ngan, Mr WS Lee.

This publication is produced by the Department of Health, 21/F Wu Chung House, 213 Queen’s Road East, Wan Chai, Hong Kong SAR. For comments on Poisoning.Comm, please send your e-mails to [email protected] This information remains the copyright of the Editorial Team and should not be reproduced without permission. It is not permissible to offer the entire documents or selections, in whatever format (hard copy, electronic or other media) for sale, exchange or gift without the written permission of the Editorial Team. Use of parts of the publication for training or educational purposes is permitted but such use should acknowledge the source of the material. All rights reserved

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