TOPIC: NEAR FATAL CASE OF AMLODIPINE POISONING IN AN INFANTINDIAN JOURNAL OF PEDIATRICS

JUNE 2013 volume 80 by Somashekar M. Nimbalkar ,Dipen vasudev patel

INTRODUCTION

• Infants contribute about 5.25% of poisoning exposure. Only one case of amlodipine poisoning is reported in infants

and the child recovered after treatment.

• The authors report an 11 month old infant with nearly fatal amlodipine poisoning.

CASE REPORT

• A 11 month old infant received 6 doses of 15mg of amlodipine which was dispensed against prescribed amoxicillin for lower respiratory tract infection.

• He presented with vomitting and reduced activity.

• He worsened over few hours with increased lethargy, bradychardia, respiratory distress and progressive loss of consiousness , irregular heart sounds, bilateral creptations over chest and hepatomegaly.

• His blood sugar was 382mg/dl.

• On admission he had anemia.

• Blood pressure remained at 70/40 mm Hg

• He was progressed to hypotensive shock within three hours of admission.

INVESTIGATION ADMISSION 24HOURS 48 HOURS 72 HOURS

s.Creatinine(mg/dl)(0.6-1.5mg/dl)

0.59 0.81 0.49 0.34

s.Urea(8-25mg/dl) - 108 56 8

s.Sodium(135-148mmol/l)

129 124 131 146

s.Potassium(3.5-5.5 mmol/l)

5.8 5.7 3.6 21.9

s.Calcium(8-11mg/dl)

9.34 10.6 11.05 -

INVESTIGATION ADMISSION 24 HRS 48 HRS 72 HRS

Alanine transaminase (u/l)

44 - - 124

Aspartate transaminase(u/l)

112 - - 622

s.Total bilirubin(mg/dl) 0.24 - - 0.49

Haemoglobin(g/dl) 8.2 9.7 -

HCO3(22-29 meq/l) 17 19.3 23.6 -

PCO2(41-51mm hg) 33.4 34.6 34.6 -

PO2(30-40 mm hg) 267 356.1 398.6 -

• His blood sugar was found increased because Calcium channel blockers bind to alpha unit

of L-type channel results in impaired secretion of insulin results in hyperglycemia.

• CCB poisoning also results in insulin resistance.

• The maximum therapeutic dose of amlodipine is 0.6mg/kg per day. But the 6kg infant received 15 mg three times a day.

• Amlodipine three times a day for two days (about 12.5 times maximum dose of amlodipine).

TREATMENT

• He received mechanical ventilation.• Fluid therapy with normal saline was given.• His parameters only improved after giving

insulin 0.5-1 unit/kg/hr was given for (15 hours) along with calcium gluconate infusion for (72 hours).

• He was treated with adrenaline which is a powerful cardiac stimulant .It acts on beta receptors and increases heart rate, cardiac output.(as CCB in higher dose causes decrease in heart rate, decrease cardiac output)

• Calcium channel blockers usually causes negative ionotropic effect ( weaken heart contraction and slows the heart rate).

• So positive ionotropes such as dopamine, epinephrine are given to change the force of heart contractions and improves the heart rate.

• To manage renal failure , oliguria(decrease in urine output), pulmonary edema, congestive cardiac failure peritoneal dialysis was initiated at 24 hours of admission and continued for 48 hours.

Child improved hence insulin infusion was tapered and stopped after 15 hours.

Ionotropes was tapered after 48 hours. Calcium gluconate stopped after 72 hours. Liver enzymes increased after 72 hours of

ingestion without develpoment of jaundice. Patient was discharged after 10 days .

DISCUSSION

• Calcium channel blockers are a potential source of risk for children due to the high dosage from strength ,in relation to the body weight.

• A single dose of 10 mg nifedipine tablet was associated with the death of an infant.

• Amlodipine has large volume of distribution and half life is 35-45 hours and overdose causes prolonged calcium channel blockers toxicity.

• Animal studies have shown insulin improves myocardial infraction during shock induced by calcium channel blockers toxicity.

• The author’s says that insulin therapy can be recommended as first line therapy for calcium channel blockers toxicity.

CONCLUSION

• It is said that hyperinsulinemia therapy is beneficial in patients with calcium channel blockers induced hypotension , hyperglyceamia and acidosis.

• High dose insulin therapy and other standard therapies discussed above are used in combination.

• The prescribers should avoid these kind of medication errors in order to improve patient safety.

REFERENCES

• Bronstein Ac, Spyker DA , Cantilena Jr ,Green JL, Rumack BH,2008.

• Annual report of American association of poison control centres

• National poison data system (26 th annual report).

• Spiller HA, milliner BA amlodipine poisoning in an infant by J.Med toxicol 2012 ;8; 179-182

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