9.9. POISONING/ OVERDOSAGE WITH CALCIUM CHANNEL BLOCKERS

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Antihypertensive drugs.

Purpose of assistance

1. To weaken the absorption of oral drugs in the gastrointestinal tract by using certain binders (activated charcoal), especially in case of long-term poisoning.
2. Early protection of the respiratory tract, as a rapid deterioration of the patient’s level of consciousness may occur.
3. Ensuring adequate ventilation, oxygenation and treatment of hypoperfusion.

Description of the patient

Calcium channel blockers interrupt the movement of calcium between cell membranes. They are used to control hypertension, certain arrhythmias, prevent spasm of cerebral vessels, and angina pectoris. The patient may have:

1. Bradycardia.
2. Hypotension.
3. Decreased conduction through the atrioventricular node.
4. Cardiogenic shock.
5. Hyperglycemia.

Inclusion criteria

Patients using/injected with calcium channel blockers.
Examples of calcium channel blockers:

a) amlodipine;
b) diltiazem;
c) felodipine
d) isradipine;
e) nicardipine;
e) nifedipine;
e) nisoldipine;
e) verapamil.

Exclusion criteria

No recommendations.

Management of the patient

Status assessment

1. Perform a complete initial examination (ABCD), if indicated, undress the patient and then cover him to keep warm.
2. Assess vital signs, including body temperature.
3. Apply cardiac monitoring, assess for arrhythmias, then record a 12-lead ECG.
4. Check your glucose level.
5. Monitor pulse oximetry and ETSO2 for respiratory decompensation.
6. Determine the specific drug (determine the onset of action – immediate or delayed) – name, time of administration, quantity.
7. Collect anamnesis regarding diseases of the cardiovascular system or prescribed other drugs for other diseases.
8. Collect medical history relevant to this case.
9. Do a physical examination.

Treatment and intervention

1. Administer sorbitol-free activated charcoal (1 g/kg) orally. If there is a risk of a rapid change in consciousness, do not use an oral drug without first obtaining control of the patient’s airway.

2. Use atropine sulfate for symptomatic bradycardia:

a) adults: 1 mg IV every 5 minutes, maximum dose – 3 mg;
b) children: 0.02 mg/kg (maximum dose – 0.5 mg) with an interval of 5 minutes, the maximum total dose is 1 mg.

3. Apply calcium gluconate or calcium chloride:

a) calcium gluconate:

• • • • adults: calcium gluconate – 2-6 g slowly by syringe through an IV catheter over 10 minutes;
      • children: 60 mg/kg slowly by syringe through an IV catheter over 10 minutes;

b) calcium chloride:

• • • • adults: 0.5-1 g slowly by syringe through an IV catheter (50 mg/ml);
      • children: 20 mg/kg (0.2 ml/kg) slowly by syringe through an IV or IV catheter (50 mg/ml).

Maximum dose 1 g or 10 ml (calcium gluconate is a safer option, as calcium chloride can cause tissue damage in children).

4. Consider intravenous fluid bolus (saline solution or combined drug with sodium chloride + potassium chloride + sodium lactate + calcium chloride) 20 mg/kg up to 2 L.

5. Use vasopressors after adequate fluid resuscitation for hypotension (see “Shock” guideline for doses in children and adults).

6. If atropine, calcium and vasopressors did not relieve symptoms of bradycardia, use:

a) adults: glucagon, initial dose of 5 mg followed by 1 mg every 5 min by syringe through an IV catheter (5-15 mg may be required for effect);< br />b) children:

• • • • glucagon 1 mgwith a syringe through an IV catheter (with a body weight of 25-40 kg) – every 5 minutes, if necessary;
      • glucagon 0.5 mg by syringe through an IV catheter (weight less than 25 kg) – every 5 minutes, if necessary.

7. Apply percutaneous electrocardiostimulation in the absence of response to primary pharmacological interventions.

8. For seizures, use midazolam (benzodiazepine of choice):

a) adults: midazolam 0.1 mg/kg IV followed by an increase in the dose to 2 mg slowly IV injection over 1-2 minutes with each increase with with a maximum single dose of 5 mg (reduction by 50% in patients 69 years and older);
b) children: midazolam 0.1 mg/kg IV followed by an increase in the dose to 2 mg slowly IV within 1- 2 minutes with each increase with a maximum single dose of 5 mg or midazolam 0.2 mg/kg (max dose – 4 mg).

Patient safety

Percutaneous electrocardiostimulation does not always allow you to see and correct hypotension, even if it is successfully displayed on the monitor.

Useful information for training

Key points

1. Although most calcium channel blockers cause bradycardia, dihydropyridine calcium channel blockers (eg, nifedipine, amlodipine) may cause reflex tachycardia immediately after administration. With increasing intoxication, the patient may develop bradycardia.
2. Avoid the use of calcium chloride and calcium gluconate in a patient on cardiac glycosides, as their use can lead to rapid intoxication and concomitant fatal arrhythmia, but this is a historically old theory and it is not supported by facts.
3. Glucagon has side effects in the form of increased vomiting when used in these doses, so prophylactic use of ondansetron should be considered.
4. One pill can kill a baby. It is very important to carry out a thorough assessment of the drugs that the baby could have had access to and to bring to the reception department drugs that are suspected of being used by the baby.
5. Calcium channel blockers can cause many different types of rhythms, ranging from sinus bradycardia to complete heart block.
6. Hyperglycemia is the result of blockade of L-type calcium channels in the pancreas. This makes it possible to distinguish the action of calcium channel blockers from the action of beta blockers. There may also be a relationship between the severity of poisoning and the degree of hyperglycemia.
7. Atropine has minimal or no side effects (probably more useful in mild overdoses).

Hypotension and bradycardia may be mutually exclusive, and blood pressure may not respond to bradycardia treatment.

Corresponding evaluation results

1. Careful ECG monitoring to detect changes and arrhythmias.
2. Periodic re-examination is critical because such patients tend to deteriorate with severe hypotension.

Key elements of documentation

1. Re-examine and document signs and symptoms as the patient’s clinical condition may worsen.
2. Identification of the possible etiology of poisoning.
3. Time of manifestation of symptoms and time of initiation of treatment, based on the specificity of poisoning.
4. Therapy and response to therapy.

Criteria for the effectiveness of aid provision

1. Early airway management in patients with a rapidly deteriorating condition.

2. Detailed impact history:

a) time of administration/exposure;
b) route of exposure;
c) amount of drug or received toxin (carefully collect the remains of all possible drugs and substances) ;
d) consumption of alcohol or other toxins.

3. Selection of the appropriate protocol and patient management.

4. Periodic documentation of the results of repeated assessment of the patient’s condition.