This document discusses antihypertensive drug overdose and management. It describes a case of a 64-year-old male brought to the emergency department with confusion, weakness, and electrolyte abnormalities. His history indicates hypertension treated with oral medications. The document then outlines various classes of antihypertensive drugs and their associated toxic effects, including diuretics causing electrolyte abnormalities, sympatholytics causing hypotension and bradycardia, and vasodilators causing hypotension. Management of overdose involves supporting airway, breathing, and circulation. Specific treatments are recommended for angioedema, hypotension, and electrolyte disturbances.

1. Anti Hypertensive Drugs Overdose
Dr. Runal Shah
MEM PGY-1,
KDAH, Mumbai.

2. Case scenario
 64 year male, brought to ED, in confused state, by the
neighbors, complaints being generalized weakness developing
over past one week, loss of appetite, easy fatigability,
increased urination. Past history s/o Hypertension on oral
medication.
 ED workup – Na-126, K-2.8, Cl-90, Creat-1.45, Bicarbs-22,
Lact-2
 ECG –

3. Anti Hypertensive agents
 Diuretics
 Acetazolamide
 Thiazides
 Loop diuretics
 K+ sparing diuretics
 Sympatholytics
 Alpha-1 blockers
 Central Alpha-2 agonists
 Nor-Epinephrine release
inhibitors
 ACE Inhibitors
 ARBs
 Vasodilators
 Arteriolar dilatation –
Hydralazine, Minoxidil
 Arteriolar + Venous
dilatation – Nitroprusside

4. Diuretics
 Toxidrome :
 Tachycardia
 Hypotension, Hypovolemia
 Electrolytes Abnormality
 Hypo / Hyperkalemia
 Hypo / Hypercalcemia
 Hypomagnesemia
 ECG changes – Wide QRS, Tall T, Prolong QTc, these changes
precipitates to Arrhythmias (Tachydysrhythmias)

5. Diuretics contd..
 Loss of Urinary Bicarb – resulting in Metabolic acidosis most
commonly seen with Acetazolamide.
 Loop diuretics use can cause hypomagnesemia,
hypocalcemia, Hypochloremic hpokalemic alkalosis, in liver
deranged pt can lead to Hepatic encephalopathy, N number of
drug reactions are encountered.
 Thiazides – Hypercalcemia, Hyperuricemia, Fatal/ non-fatal
Hyponatremia
 K+ sparing – Hyperkalemia is the main side effect

6. Sympatholytics
 Toxidrome:
 Hypotension
 Bradycardia
 CNS depression
 Hemolytic anemia (Idiosyncratic reaction to MethylDopa)

7. Sympatholytics contd..
 Alpha-1 Blockers decreases Peripheral venous
resistance (PVR) – Orthostatic hypotension as 1st
dose side effect (30-90 min after taking drug)
 Clonidine : Central Alpha-2 agonist + Mu-receptor
agonist
 Toxidrome mimics like opioid overdose –
 Bradycardia, Hypotension, Miotic pupils, Somnolence,
Hypothermia, Apnea(later)

8. Vasodilators
 Toxidrome:
 Hypotension
 Tachycardia
 Increased Myocardial Oxygen demand
 Lupus like syndrome (Idiosyncratic to Hydralazine)
 Thiocyanate and Cyanide toxicity

9. Vasodilators contd..
 Lupus like syndrome –
 Continuous treatment can cause
 Auto-antibody mediated
 Risk factors – high dose, female sex, slow actylators
 Symptoms - Arthralgia/ itis, fever, pericardial effusion
 Manage with Anti inflammatory agents
 Prompt discontinuation of Hydralazine is required
 Cyanide and Thiocyanate toxicity –
 On higher infusion rates of Nitroprusside >5 mcg/kg/min
 Sodium Thiosulfate to administer as antidote

10. ACE-I & ARBs
 Toxidrome:
 Hypotension
 Hyperkalemia
 Cough
 Angioedema (Idiosyncratic)

11. Captopril induced Hypotension & reversal
with Naloxone?!

12. Management
 Airway (Angioedema related airway compromise)
 Breathing
 Circulation – Hypotension & Tachycardia to manage with fluid
boluses of 0.9NS
 Refractory cases – Phenylephrine iv (100-200mcg/min iv and
then maintenance 40-60mcg/min)
 ?Naloxone – limited role (evidence not sufficient)
 Angioedema – IV Methyl-Pred 125mg iv, Diphenhydramine
50mg iv, IM Epinephrine 0.3mg sc
 Supportive management
 Charcoal – if ingestion <1hr back..

13. Workup
 Blood Investigations – Electrolytes, Blood gas, Renal Profile
 Urine routine, urine electrolytes
 Screening 2D echo
 Imaging – CT/MRI
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 Refractory Hypotension despite IV fluids
 Angioedema with airway compromise
 Hypo-Hyperkalemia with ECG changes / arrhythmias
 Hyponatremia requiring prompt correction or symptomatic
Disposition

14. Thank you..
Ref : clinicalkey.com, pubmed.gov, Goodman & Gilman’s Pharmacology,