Friday, January 29, 2016

Iron sucrose vs Iron Dextran




Iron Dextran 50mg Fe/ml Injection (2ml ampoule)
COSMOFER
Iron Sucrose 100mg/5ml Injection (5ml ampoule )
VENOFER
Availability 
(Prescribing category)
  • 100mg of Iron in 2ml 
  • (B)
  • 100mg of Iron in 5ml 
  • (B)
Indication
  • Treatment of iron deficiency for >14 years old
  • Treatment of iron deficiency for adult and children
  • In children, recommended to not exceed 0.15ml/kg body weight one to three times per week
Dosing and Administration
  • An initial test dose of 0.5ml should be given over the desired route
  • Can be given as multiple doses of 2 mL (equivalent to 100 mg elemental iron, based on a concentration of 50 mg elemental iron per mL).
  • Can also be given as a single, total dose infusion up to 20mg iron/kg body weight
  • For severe iron deficiency anaemia, 1 to 2ml daily given by deep IM.
  • Dosage is individualized according to total iron deficit
  • An initial test dose is required only if patient has allergies history
  • Given over multiple infusions, with a maximum individual dose of 10 to 15 mL (equivalent to 200 to 300 mg elemental iron, based on a concentration of 20 mg elemental iron per mL)
  • By IV drip infusion, slow IV injection or directly into the venous limb of dialyser. Cannot be given IM.
Number of doses required
  • Can be administered in one or two visits (Frequent visiting not necessary)
  • If patient has frequent visits low doses can be administered
Cost
  • The least expensive
  • More expensive
Adverse Effects
  • Comparable
  • Less nephrotoxic In CKD patients stage 3 & 4 compared to iron sucrose
  • Comparable
  • More nephrotoxic in CKD patients stage 3&4 compared to iron dextran

RECOMMENDATIONS
  • If total dose of iron needed is high, then iron dextran is preferred since the adverse events are not any higher than iron sucrose.
  • But initial test dose is necessary before giving full desired dose for iron dextran
REFERENCES
  1. www.uptodate.com
  2. Product Leaflets
  3. Comparative rates of adverse events with different formulations of intravenous iron, http://onlinelibrary.wiley.com/doi/10.1002/ajh.23322/full
  4. Safety Issues With Intravenous Iron Products in the Management of Anemia in Chronic Kidney Disease, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2670525/

Haloperidol Poisoning Management

Clinical presentation of poisoning
SEVERITY
CLINICAL PRESENTATION
MILD
  • Sedation, small pupils, orthostatic hypotension.
  • Anticholinergic symptoms: Dry mouth, absence of sweating, increased heart rate, urinary retention
SEVERE
  • Coma, seizures, respiratory arrest
  • ECG- shows QT prolongation and occasionaly QRS prolongation
  • Hypothermia or Hyperthermia may occur
  • Extrapyrimidal side effects- Jaw muscle spasm, rigidity, bradykinesia, pill-rolling tremor, rolling of the eye ball
MANAGEMENT AND TREATMENT
  1. Emergency and Supportive Measure
  2. Maintain an open airway and assist ventilation if necessary
  3. Gastric lavage (if few hours after ingestion) followed by activated charcoal
  4. Cardiac monitoring for at least 24-48hr.
Symptoms
Adult dose
Children Dose
Acute dystonic reactions
  • Give IV Diazepam 0.1-0.2mg/kg, OR
  • IM/IV Diphenhydramine 0.5-1mg/kg  OR
  • Anticholinergic agent (eg: Oral, IM, or IV Benztropine 1-2mg, bd or tds
  • IV,IM, or oral Benztropine: 20 micrograms/kg (unlicensed indication
Hypotension
  • Fluid administration using normal saline 10-20ml/kg, and alpha-adrenergic agent (eg:Noradrenaline, Phenylephrine)
  • Up to 20ml/kg/dose titrate to hypotension reversal (Lexicomp indication for hypovolemic septic shock)
Ventricular Arrythmias








Recurrent Torsades de pointes
  • **Lignocaine, Phenytoin. Severe QT prolongation may need Magnesium
  • Severe QRS prolongation treat with Sodium Bicarbonate 1-2mEq/kg IV bolus and repeat as necessary
  • Magnesium, Isoprenaline or overdrive pacing
  • Overdrive pacing is preferred
  • IV Isoprenaline 0.2 micrograms/minute and titrated to maintain a heart rate of 100 beats per minute
  • IV Magnesium sulphate 8mmol over 10-15 minutes, repeated once if necessary
  • Magnesium : Clinical experience in children is lacking, but based on the recommendations for management in  adults, doses of 0.08-0.2 mmol/kg (0.04-0.1 ml/kg of 50% solution) may be considered appropriate
Seizures
  • IV Diazepam 0.1-0.2 mg/kg
  • **Dosing specifically in poisoning case is not present.
** Dosings for these medications in poisoning cases were not extensively studied, suggest to use dosing recommendation for the respective indication it is used for
REFERENCES
1. Sarawak Handbook 3rd edition
2. Poisoning & Drug Overdose 3rd edition

Thursday, January 28, 2016

Asthma In Pregnancy and Lactation

PREGNANCY:



Inhaled beta agonists
  • Salbutamol and terbutaline are safe to use during pregnancy
  • Limited studies are available on long-acting beta agonists such as salmeterol and eformoterol, which are thus categorised as B3
  • As the majority of these studies analysed long-acting beta agonists in combination with other asthma drugs and have not shown any significant increase in harm
  • maternal plasma concentrations after inhaled salmeterol or eformoterol are very low or virtually undetectable.
  • The Asthma Management Handbook discourages starting treatment with long-acting beta agonists in the first trimester, but does not advocate withdrawing them if they are necessary to control the patient's symptoms
Inhaled corticosteroids
  • Using inhaled corticosteroids during pregnancy has been associated with a decreased risk of low birthweight babies.
  •  A study of women with asthma exacerbations found a 55% reduction in subsequent exacerbations and hospital admissions in those who used beclomethasone compared to those who did not.
  • Women should be advised to continue their preventive drugs during pregnancy
  • Budesonide is a category A drug. The Asthma Management Handbook recommends switching to budesonide before pregnancy
  • Comparisons between different inhaled corticosteroids and doses are limited
  • The relationship between gestation and adverse events has not been explored in depth, but available studies suggest there is no greater risk with using inhaled corticosteroids in any particular trimester
Oral corticosteroids
  • Prednisolone, has been shown to be under-prescribed in acute asthma exacerbations during pregnancy, leading to persistent and recurrent asthma symptoms two weeks late
  • There have been reports of an increased risk of cleft lip with or without cleft palate from first trimester use, however, the data were from studies with a small sample size that included corticosteroid use for other conditions that generally needed higher and more frequent doses
  • It is also difficult to separate the potential effects of oral corticosteroids from the potential effects of poorly controlled maternal asthma as oral corticosteroids are generally indicated for severe asthma.
  • It is necessary to monitor blood glucose if oral corticosteroids are used in pregnancy, especially if there is gestational diabetes.
Cromolyns and leukotriene receptor antagonists
  • Inhaled cromolyns are probably safe to use in pregnancy.
  • No well-designed studies have assessed the sole use of leukotriene receptor antagonists, such as montelukast, during pregnancy.
  • Studies have shown an increase in adverse events with use, but these studies did not exclusively test montelukast during pregnancy
  • Montelukast should be used in pregnancy only if clearly indicated and only after considering more effective and safer treatment
Anticholinergics
  • Currently there are no published controlled data on the use of inhaled anticholinergics during pregnancy and their use should be reserved as a last option.
  • Nebulised ipratropium bromide with inhaled beta agonists and intravenous corticosteroids has been recommended for management of acute asthma during pregnancy
LACTATION:
  • Systemic absorption of inhaled drugs is generally minimal and causes little harm to the infant.
  • The infant's exposure is 10 to 1000 times less than during pregnancy.
  • The amount ingested through the mother's milk is far below the therapeutic level for an infant – mostly under 3% of a therapeutic dose per kilogram bodyweight
Montelukast
  • There are no human studies of montelukast in breastfeeding, but animal studies have detected excretion into milk. 
  • Alternative treatment with short-acting beta agonists, long-acting beta agonists or inhaled corticosteroids should be considered during breastfeeding, particularly as montelukast is taken orally
Prednisolone
  • Prednisolone at recommended doses is thought to be safe since the amount excreted in human milk is low with daily doses up to 80 mg. 
  • It is recommended to withhold feeds for four hours after each dose to reduce infant exposure. 
  • Prednisolone is preferred over prednisone, as prednisone is converted to prednisolone in vivo, causing a double peak of parent medicine and metabolite
SUMMARY:
  • Drugs that can be used as normal in pregnancy
    • Short Acting Beta2 agonist, Long Acting Beta2 Agonist, Inhaled Corticosteroids, Oral and Intravenous Theophylline
  • Steroids PO can be used as normal in severe asthma
  • If Leukotriene Receptor Antagonists required to control the asthma, use is not contraindicated
REFERENCES:
  1. www.uptodate.com
  2. Medscape, http://www.medscape.org/viewarticle/569862
  3. http://www.guidelines.co.uk/btssign/asthma-in-pregnancy
  4. http://www.australianprescriber.com/magazine/36/5/150/3#t1