Unclassified Adenosine

Class IA: Quinidine

A naturally occurring nucleoside and G-pro-tein with its own specific adenosine receptors; IV boluses of adenosine are indicated to rapidly terminate reentrant and theophylline-induced SVTs.

Mechanisms: Provides an evanescent (10 sec) calcium entry block and increases AV nodal refractory period; reduces action potentials and reduces automaticity.

Toxicities: Transient asystole, atrial fibrillation, hypotension, bronchospasm. All toxicities are potentiated by the antiplatelet agent, dipyri-damole, an adenosine uptake inhibitor. Higher doses are required for methylxanthine overdoses due to adenosine receptor blockade. Treatment of toxicity: Supportive.

Mechanism: Na, K, and Ca channel blocker. Pharmacology: An amide local anesthetic, with excellent mucosal absorption, d-isomer of quinine, the antimalarial from cinchona bark; rapidly absorbed orally; high volume of distribution and protein binding.

Toxicity: Prolonged QT interval and widened QRS complex, ventricular tachycardia, ventricular fibrillation, torsades, hypotension, seizures, noncardiogenic pulmonary edema, cinchonism. Treatment: Decontamination — no ipecac, oro-gastric lavage; IV fluids and vasoMech (a cardiac and peripheral Na channel blocker).

Chapter 11

Miscellaneous Poisonings with Commonly Prescribed Drugs: Antibiotics, Cancer Chemotherapeutics, and Hypoglycemics

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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