Emergency Drugs

Layola, Venessa Anne Mei A.

Emergency Drugs Table 1: Mandatory Emergency Drugs Drugs

Indications

Preparations

Oxygen

For use in all medical emergencies where hypoxemia may be present

Steel cylinders (green); E tanks, 690 L

Epinephrine

Acute allergic reactions Acute asthma (not responding to adrenergic inhaler)

Nitroglycerin

Angina pectoris, Acute myocardial infarction

Ampules: 1 mg Vials: 1 and 30 mg Syringes: 0.3 and 1 mg Tablets (sublingual): 0.15, 0.3, 0.4, and 0.6 mg Spray: 0.4 mg/actuation

Oxygen can be delivered to the spontaneously breathing patient via full face mask, nasal cannulae, or nasal hood. Epinephrine is mandatory for the treatment of cardiac arrest and overwhelming anaphylaxis. However, it must be emphasized that these extreme conditions are the only situations that would require its use in the dental office emergency. There are a few clinicians who maintain the mistaken belief that epinephrine is the drug of choice in shock or shocklike states. There are three principal reasons for disputing this belief. First, in shock from almost any cause there is decreased venous return to the heart because of peripheral venous pooling. Because the peripheral action of epinephrine is primarily on the arterial side, there is little gain in promoting peripheral vasoconstrictions, which is already present because of the massive release of endogenous catecholamines (epinephrine and norepinephrine). At this point administration of epinephrine may further decrease venous return and tissue perfusion. Second, a possible deleterious effect is an increase in selective ischemia that takes place in certain viscera such as the kidney. Here, as in peripheral vessels, the blood supply is constricted in a compensatory effort to increase blood flow to the more vital brain and heart tissues. Perpetuation of this condition could be undesirable. Third, the possible precipitation of ventricular fibrillation in the ischemic and irritable myocardium is an important factor. This could be especially disastrous in the dental office where defibrillation equipment is usually not available. In early treatment of shock states the patient will benefit more from measures aimed at correction of the primary cause such as hypovolemia rather than misdirected attempts at pharmacologic correction. Desirable properties of this agent include a rapid onset of action; potent action as a bronchial smooth muscle dilator (beta2 properties); antihistaminic actions; vasopressor actions; and its actions on the

heart, which include an increased heart rate (21%), increased systolic blood pressure (5%), decreased diastolic blood pressure (14%), increased cardiac output (51%), and increased coronary blood flow. Undesirable actions include its tendency to predispose the heart to dysrhythmias and its relatively short duration of action. Epinephrine is an important drug during cardiac arrest because no other drug is capable of maintaining coronary artery blood flow while CPR is in progress, which is essential for preserving the chances of survival from cardiac arrest. Epinephrine also preserves blood flow to the brain. In the absence of drug therapy, cerebral blood flow during CPR is minimal; most blood enters the common carotid artery and flows into the external carotid branch, not the internal carotid artery. Following administration of a drug with a-adrenergic properties, such as epinephrine, cerebral blood flow is significantly increased. Because of its profound bronchodilating effects, epinephrine is also indicated for the treatment of acute asthmatic attacks unrelieved by b2-adrenergic sprays or aerosols. Side effects, contraindications, and precautions: Tachydysrhythmias, both supraventricular and ventricular, may develop. Epinephrine should be used with caution in pregnant women because it decreases placental blood flow and may induce premature labor. When used, all vital signs must be monitored frequently. Antihistamines will be of value in the treatment of the delayed allergic response and in the definitive management of the acute allergic reaction (administered after epinephrine has terminated the acute lifethreatening phase of the reaction). Antihistamines act as competitive antagonists of histamine. They do not prevent the release of histamine from cells in response to injury, drugs, or antigens, but do prevent access of histamine to its receptor site in the cell and thereby block the response of the effector cell to histamine. Thus, antihistamines are more potent in preventing the actions of histamine than in reversing these actions once they develop. Nitroglycerin Vasodilators are used in the immediate management of chest pain (such as may occur with angina pectoris or acute myocardial infarction). Two varieties of vasodilator are available: nitroglycerin (TNG) as a tablet and a spray, and an inhalant, amyl nitrite. A patient with a history of angina pectoris will usually carry a supply of nitroglycerin. Tablets remain the most popular form of TNG, although most patients prefer the translingual spray once they have used it. . Amyl nitrite, another vasodilator, is available for use as an inhalant. It is supplied in a yellow vaporole or a gray cardboard vaporole with yellow printing in a dose of 0.3 mL, which when crushed between one's finger and held under the victim's nose will act in about 10 seconds to produce a profound vasodilation. The duration of action of amyl nitrite is shorter than that of TNG; however, the shelf life of the vaporole is considerably longer. Side effects occur with all vasodilators but they are more significant with amyl nitrite. Side effects, contraindications, and precautions: Side effects of nitroglycerin include a transient pulsating headache, facial flushing, and a degree of hypotension (noted especially if the patient is in an upright position). Because of its mild hypotensive actions, nitroglycerin is contraindicated in patients who are hypotensive, but may be used with some degree of effectiveness in the management of acute hypertensive episodes. Side effects of amyl nitrite are similar to but more intense than those of nitroglycerin. These include facial flushing, pounding pulse, dizziness, intense headache, and

hypotension. Amyl nitrite should not be administered to patients who are in an upright position because the patient may feel dizzy and suffer a fall.

Table 2: Emergency Support Drugs Category

Generic

Proprietary

Alternative

Anticonvulsant

Midazolam

Versed

Diazepam

Analgesic

Morphine

Vasopressor

Methoxamine

Antihypoglycemic

50% Dextrose sol.

Glucagon

Corticosteroid

Hydrocortisone SoluCortef sodium succinate

Dexamethasone

Antihypertensive

Labetalol HCl

Normodyne

Anticholinergic

Atropine

Injectable Meperidine Vasoxyl

Phenylephrine

Noninjectables Respiratory stimulant

Aromatic Ammonia

Antihypoglycemic

Carbohydrate Decorative Many icing

Bronchodilator

Albuterol

Ventolin, Proventil

Antihypertensive

Nifedipine

Procardia

Metaproterenol

Anticonvulsant Seizures that may require acute medical intervention may be associated with epilepsy, hyperventilation episodes, cerebrovascular accidents, hypoglycemic reactions, or vasodepressor syncope. Local anesthetic overdoses or accidental intravascular injection may also require the administration of an anticonvulsant. Current management of a seizure that interferes with ventilation or persists for longer than 5 minutes includes the use of an intravenous benzodiazepine such as diazepam or midazolam. With its introduction, diazepam became the preferred anticonvulsant. Because seizure disorders are characterized by a stimulation of the central nervous and cardiorespiratory and cardiovascular systems, followed by a period of depression of these same systems, drugs that depress the systems at therapeutic does are more likely to produce postseizure complications. When barbiturates are administered to terminate seizure activity, the degree of postseizure depression is accentuated and its duration prolonged because of the pharmcologic action of the barbiturate.

If the doctor is not adapt at recognizing and managing this situation, the patient may be worse off after the seizure than during it. The benzodiazepines, unlike barbiturates, will usually terminate seizure activity without the pronounced depression of the respiratory and cardiovascular systems. Analgesic medications will be useful during emergency situations in which acute pain or anxiety is present. In most instances the presence of pain or anxiety will cause an increase in the workload of the heart (and an increased myocardial oxygen requirement) that may prove detrimental to the well-being of the patient. Two such circumstances are acute myocardial infarction and congestive heart failure. The choice of analgesic drugs includes the narcotic agonists morphine sulfate and meperidine (Demerol). Side effects, contraindications, and precautions: Narcotic agonists are potent CNS and respiratory depressants. Vigilant monitoring of vital signs is mandatory whenever these agents are used. Use of narcotic agonists is contraindicated in victims of head injury and multiple trauma; they should be used with care in persons with compromised respiratory function. Vasopressor In most emergency situations in which a vasopressor is indicated in the dental office, an agent such as epinephrine will not be the drug of choice. Epinephrine will be used primarily in the management of acute allergic reactions and is rarely employed in cases of clinically mild to moderate hypotension. One reason for this is that epinephrine elicits an extreme antihypotensive response. In addition to an increase in blood pressure, epinephrine causes an increase in the workload of the heart through its effect on heart rate and cardiac contraction; it also increases the irritability of the myocardium by sensitizing it to dysrhythmias. Vasopressors such as methoxamine (Vasoxyl) and phenylephrine (Neo-Synephrine) are drugs that produce moderate blood pressure elevations through peripheral vasoconstriction. Methoxamine is a clinically useful vasopressor with sustained action and little effect on the myocardium or central nervous system. Its vasopressor action is associated with a marked increase in peripheral resistance and no increase in cardiac output. A compensatory bradycardia accompanies the rise in blood pressure produced by methoxamine. The onset of the pressor action is almost immediate following IV administration and may persist for up to 60 minutes. After IM injection the response occurs within 15 minutes and persists for 90 minutes. Phenylephrine acts in a similar fashion, with a 5-mg IM dose causing a 30-mm Hg elevation of systolic blood pressure and a 20-mm Hg elevation of diastolic blood pressure, with the response persisting for 50 minutes. As with methoxamine, a pronounced and persistent bradycardia will be noted (average decline in heart rate from 70 to 44 beats per minute). Antihypoglycemic Glucose preparations are used to treat hypoglycemia that results either from fasting or insulin use in a patient with diabetes mellitus. If the patient is conscious, oral carbohydrates such as chocolate bar, cake icing, or cola drink will act rapidly to restore circulating blood sugar. On the other hand, if the patient is unconscious and acute hypoglycemia is suspected, intravenous administration of 50% dextrose solution is the treatment of choice. Corticosteroids will be administered in the management of an acute allergic reaction, but only after the acute phase has been brought under control through the use of basic life support, epinephrine, and

antihistamines. The primary value of the corticosteroids is in the prevention of recurrent episodes of anaphylaxis. Corticosteroids are also important in the management of acute adrenal insufficiency. The onset of intravenous corticosteroids, such as hydrocortisone sodium succinate, is delayed, but the drugs can be useful in halting the progression of a major allergic or anaphylactoid reaction. There is also the potential for encountering what appears initially to be a syncopal episode but is in reality the more serious problem of acute adrenal insufficiency in a patient chronically taking systemic corticosteroids to treat a medical condition. For this life-threatening emergency, only the prompt diagnosis and infusion of corticosteroids will be curative. Hydrocortisone sodium succinate is considered the drug of choice for the dental emergency kit. Corticosteroids are considered second-line drugs primarily because of their slow onset of action. Antihypertensive The need to administer drugs to decrease excessive elevations in blood pressure is extremely uncommon. First, the incidence of extreme acute blood pressure elevation is quite rare and, second, there are other means of decreasing blood pressure without resorting to parenteral antihypertensive drugs. Emergency Drugs Oral drugs, such as nifedipine or nitroglycerin, may be administered in most situations to provide a minor depression of blood pressure. The inclusion of a drug in this category is in response to state requirements for general anesthesia permits (and in a few states for parenteral sedation, too). Anticholinergic Atropine, a parasympathetic blocking agent, is recommended for the management of symptomatic bradycardia (adult heart rate of <60 beats per minute). By enhancing discharge from the sinoatrial (SA) node, atropine may provoke tachycardia (adult heart rate>100 beats per minute). Atropine will be of benefit in situations in which the patient has an overload of parasympathetic activity on the heart. Extremely fearful patients are likely candidates for this response. Atropine is also considered an essential drug in advanced cardiac life support (ACLS), in which it is employed in the management of bradydysrhythmias (hemodynamically significant heart block and asystole). Side effects, contraindications, and precautions: Large doses of atropine (>2.0 mg) may produce clinical signs of overdosage, including: hot, dry skin; headache; blurred near vision; dryness of the mouth and throat; disorientation; and hallucination. Administration of atropine is contraindicated in patients with glaucoma or prostatic hypertrophy. However, in life-threatening situations the benefits of atropine administration usually outweigh the possible risks. Respiratory stimulant After oxygen, aromatic ammonia is the most commonly used drug in the emergency situation. It is available in a silver-gray vaporole, which is crushed and placed under the victim's nose until respiratory stimulation is effected. Aromatic ammonia has a noxious odor and acts by irritating the mucous membrane of the upper respiratory tract, thereby stimulating the respiratory and vasomotor centers of the medulla; this in turn increases respiration and blood pressure. Movement of the arms and legs often occurs in response to inhalation of ammonia. This too acts to increase the return of blood from the periphery and aids in raising blood pressure, especially if the patient has been positioned properly.

Side effects, contraindications, and precautions: Ammonia should be employed with caution in persons with chronic obstructive pulmonary disease (COPD) or asthma because its irritating effects on the mucous membranes of the upper respiratory tract may precipitate bronchospasm. Antihypoglycemic agents will be useful in the management of hypoglycemic reactions occurring in patients with diabetes mellitus or in the nondiabetic patient with hypoglycemia (low blood sugar). The diabetic patient will usually carry a ready source of carbohydrate such as a candy bar or hard candy. Such items should also be available in the dental office for use in the conscious patient with hypoglycemia. Bronchodilator Asthmatic patients and patients with allergic reactions manifested primarily by respiratory difficulty will require the use of bronchodilator drugs. Although epinephrine remains the drug of choice in the management of bronchospasm, its wide ranging actions on systems other than the respiratory tract has resulted in the introduction of newer, more specific agents known as b2-adrenergic agonists. These agents, of which albuterol is an example, have specific bronchial smooth musclerelaxing properties (b2) with little or no stimulatory effect on the cardiovascular and gastrointestinal systems (b1) . In the dental situation in which the patient's true cardiovascular status may be unknown, b2 agonists appear more attractive for management of the acute asthmatic episode than agents that have both b1 and b2 agonist properties, such as epinephrine and isoproterenol. Bronchodilators must be administered precisely as directed. One to two inhalations every 4 to 6 hours is the recommended dosage for albuterol. Nebulized epinephrine (e.g., Primatene-Mist â ) should be administered one to two inhalations per hour. In situations in which these nebulized agents fail to terminate the attack, other bronchodilators (e.g., epinephrine, aminophylline, isoproterenol) must be administered parenterally (intramuscularly or subcutaneously). Side effects, contraindications, and precautions: Albuterol, like other b2 agonists, may have a clinically significant cardiac effect in some patients. This response is less likely to develop with albuterol than with other bronchodilators, thus its selection for the emergency kit. Metaproterenol, epinephrine, and isoproterenol mistometers are more likely to produce cardiovascular side effects, including tachycardia and ventricular dysrhythmias.

Table 3: Advanced Cardiac Life Support Drugs Drug

Indication

Antiarrhythmics Lidocaine

Ventricular tachycardia, pulseless, ventricular tachycardia, or ventricular fibrillation

Procainamide

Ventricular tachycardia, pulseless ventricular tachycardia or ventricular fibrillation

Bretylium

Ventricular tachycardia, pulseless ventricular tachycardia or ventricular fibrillation

Verapamil, diltiazem

Atrial flutter or atrial fibrillation, paroxysmal supraventricular tachycardia

Adenosine

Paroxysmal supraventricular tachycardia

Atropine

Bradycardia, asystole, first-degree and Mobitz type I atrioventricular block, Mobitz type II and thirddegree block

Magnesium

Torsades de pointes, ventricular fibrillation

ß blockers (e.g., propranolol)

Atrial flutter or atrial fibrillation, refractory ventricular tachycardia or ventricular fibrillation

Inotropes Epinephrine

Ventricular fibrillation, asystole, pulseless, electrical activity, bradycardia

Norepinephrine

Refractory hypotension

Dopamine

Bradycardia, hypotension

Dobutamine

Congestive heart failure

Isoproterenol

Refractory bradycardia

Digitalis

Atrial flutter, fibrillation

Amrinone

Refractory congestive heart failure

Vasodilators/Antihypertensives Nitroprusside

Hypertension, acute heart failure

Nitroglycerin

Hypertension, acte heart failure, anginal pain

Others Sodium bicarbonate

Hyperkalemia, metabolic acidosis with bicarbonate loss, hypoxic lactic acidosis

Furosemide

Acute pulmonary edema

Morphine

Acute pulmonary edema, pain and anxiety

Thrombolytic agents (e.g., anistreplase)

Acute myocardial thrombosis

Table 4: Antidotal Drugs Category

Generic

Proprietary

Alternative

Narcotic antagonist

Naloxone

Narcan

Nalbuphine

Benzodiazepine antagonist

Flumazenil

Mazicon

Antiemergence delirium Physostigmine

Antilirium

Vasodilator

Procaine

Novocain

Table 5: Emergency Drug Kit Drug

Indications

Epinephrine (Adrenalin)-1:1000 anaphylaxis, cardiac arrest

Adult Dosage and Route of Administration 0.5 ml intravenously

Methylprednisolone sodium cardiac arrest, anaphylaxis, acute 125 mg intravenously, given succinate (Solu-Medrol)-125 mg adrenocortical insufficiency slowly Monovile Sodium bicarbonate–7.5%

cardiac arrest

1 mEq/kg intravenously initially, then half this every 10 minutes

acute allergic reaction, Diphenhydramine (Benadryl) 10 extrapyramidal reaction to mg/ml phenothiazine

5 ml intravenously

Aromatic spirits of ammoniacrush ampules

one ampule, by inhalation

syncope

Glyceryl trinitrate–0.6 mg tablet angina pectoris

one tablet sublingually

Morphine sulfate–15mg/ml

1 ml subcutaneously or intravenously

myocardial infarction

Phenylephrine hydrochloride (Neo-Synephrine Hydrochloride) toxic reaction to local anesthetic 1 to 2 ml intravenously – 1:500 Dextrose in water–5%

hypovolemia, IV route for drug administration

1000 ml IV drip

Diazepam– 5 mg/ml

severe or prolonged convulsion as in toxic reaction to local anesthetic

1 to 8 ml intravenously (titrated)

Naloxone hydrochloride(Narcan) narcotic depression –0.4 mg/ml

1 ml intravenously or intramuscularly

Isoproterenol hydrochloride aerosol–0.25%

bronchospasm

one or two inhalations

Physostigmine salicylate – 1mg/ml

CNS depression following diazepam administration

0.5 to 2 ml intravenously (slow titration)

Atropine sulphate–0.1 mg/ml

bradycardia with hypotension

0.5 - 1.0 mg IV