An Unusual Presentation

ABSTRACT

• Organo Phosphate / Insecticide ingestion is the most common modality of suicide in India, Which causes excessive secretions [Cholinergic effect] in our body.
• Anti-Histamines are groups of drugs that are used in allergic reactions and are also known to have an effect in decreasing secretions [Anti-Cholinergic effect] in our body.
• What if a person consumes both at the same time? Will both drugs compete to nullify the effect or not?

CASE REPORT

28 years Gentleman with no comorbids and no known drug allergy presented to ER at 8PM on 17/8/2021 with alleged H/O consumption of monocrotophos 36% [OPC] around 30ML and TAB.CETIRIZINE 10mg tablets* 50nos [total aggregate of 500mg] at his residence around 10AM [the same day]. He was said to be in depression following demise of his mother recently. He was
apparently normal till 4PM after which he had one episode of vomitting (containing food particies, non blood stained) and giddiness.

He confessed to his friend that he has consumed the above-mentioned medications. Intially, he was rushed to government general hospital around 5PM where gastric decontamination was done and activated charcoal was introduced
through a nasogastric tube. He was also treated with INJ.PRALIDOXIME 3gm intravenously. He consumes ethanol occasionally.

ON INITIAL EVALUATION IN ER

AIRWAY
Patent, self maintained
BREATHING
RR – 20/ min, Spo2 – 99% RA, B/L air entry equal, no added breath sounds, single breath count >10
CIRCULATION
BP – 160/ 100 mmHg. HR – 112/ min,
CVS – S1S2 ⨁, no murmur, JVP – Normal, B/L PPWF ⨁,
PA – Soft, non-tender, no organomegally, bowel sounds heard.
DISABILITY
GCS – E4V5M6 [15/ 15]
B/L pupils pin point – Sluggishly reacting to light 1mm
CBG – 149mg/dl

• Fasiculations noted in B/L Quadriceps femoris muscle , B/L lower eyelid and lips.

EXPOSURE

• • 16 F Ryles tube with activated charcoal in place.
  • 18 G venflon in dorsum of right hand.

ECG

• Rate ≃ 115/ min
• Sinus Rythm
• Normal Axis
• S1Q3T3 Pattern
• No other specific ST – T Changes

ABG (RA)

pH – 7.348
PCO2 – 48.2 mmHg
PO2 – 71 mmHg
BE – 1 mmol/ L
HCO3 – 26.5 mmol/ L
TCO2 – 28 mmol/ L
SO2 – 93%
LAC – 2.11 mmol/ L

PT-INR – 0.99
CHEM – 8

Na+ – 141 mmol/ L
K+ – 3.3 mmol / L
Cl- – 106 mmol/ L
ica – 1.16 mmol/ L
GLU – 124 mg/ dl
BUN – 13 mg/ dl
CREAT – 0.9 mg/ dl
HCT – 49% PCV
HB – 16.7 g/ dl

PATHOPHYSIOLOGY OF OPC

PHARMACOLOGY OF ANTI-HISTAMINES

• Blocks HI – Histamine receptors.
• Anti-Allergic – Suppression of leukotriene and pro Inflammatory cytokine production.
• Anti-inflammatory effect – Decrease in production of granulocytic macrophage factor

SIDE EFFECTS

• Depression of CNS – (Disorders of coordination, fatigue, dizziness, diplopia, tremor, euphoria, nervousness, insommia).
• Disturbance of GI Functions – (increased appettie, nausea, vomitting, constipation of diarrhea).
• M- cholino blocking activity – (dryness of mucous nembranes, blurred vision, impotence, ischuria, tachycardia, psychosis).

PHARMACO KINETICS

• Action of drug noted within 30 – 60 minutes of post-consumption.
• Half life 8 – 10 hours.
• Eliminated by kidneys (apparent total body clearance – 53 ml/min).

BACK TO CASE REPORT – FOLLOW UP

• Patient was shifted to ICU and was started on INJ Atrophine infusion in view of bradycardia due to parasympathetic overactivity. TTM not used.
• The next day around 4AM, he developed severe respiratory distress due to respiratory muscle weakness secondary to OPC induced excessive acetylcholine at neuromuscular junction. He was intubated and connected to a mechanical ventilator. He was slowly weaned off from supports and patient discharged on
  4/9/2021.

BLOOD INVESTIGATION

PROPOSED THEORY

• We have received another patient with alleged history of accidental consumption of OPC (chlorpyrifos) of 20ml at his residence around 8pm. He was brought to ER at 11pm the same day. On arrival at the ER he was agitated, with secretions
  pooling through his oral cavity.
• Comparing both cases, there were no secretions noted in our former patient uptill 18 hours of post consumption of OPC which could be due to anti-cholinergic effect of anti- histamines.
• Hence it is concluded that Anti-histamines has a protective role on the airway by delaying onset of respiratory distress due to secretions caused by organophosphates.

Hence it is concluded that Anti-histamines has a protective role on the airway by delaying onset of respiratory distress due to secretions caused by organophosphates.

REFERENCE

• https://www.ncbi.nlm.nih.gov/books/NBK482318/
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4694283/
• https://pubmed.ncbi.nlm.nih.gov/2892445/
• https://pubmed.ncbi.nlm.nih.gov/2866055/
• https://pubmed.ncbi.nlm.nih.gov/1677249/
• https://pubmed.ncbi.nlm.nih.gov/1979802/
• https://gsconlinepress.com/journals/index.php/gscbps/article/view/gscbps-2021-0024
• https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=organophosphate+and+cetrizine+&btnG=#d=gs_qabs&u=%23p%3DGNgnndDSoZIJ
• https://pesquisa.bvsalud.org/portal/resource/pt/emr-40605
• https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=organophosphate+and+cetrizine+&btnG=#d=gs_qabs&u=%23p%3DmC8908oRpC0J
• http://www.fao.org/3/w5715e/w5715e04.htm#:~:text=Severe%20poisoning%20will%20affect%20the,extremities%20and%
20the%20respiratory%20muscles.
• https://www.researchgate.net/publication/263842305_ANTIHISTAMINES_PROMISING_ANTIDOTES_OF_ORGANOPHOSPHORUS_POISONING

Dr.Silvera Samson
MRCEM Resident – Department of Emergency Medicine