Corrigenda

Abstract

Massicotte A. A practice tool for the new oral anticoagulants. Can Pharm J (Ott) 2014;147:25-32. (Original DOI: 10.1177/1715163513513869).

In Table 3 of the above article, there were several footnotes that were incorrectly referenced. The corrected table appears below. Table 3

Significant drug interactions.^{1-5,7,8,11,12}

Type of interaction	Outcome	Dabigatran	Rivaroxaban	Apixaban
Pharmacokinetic	Increase of at least 50% in anticoagulant plasma concentrations	Amiodarone a	Clarithromycina,b	*Itraconazolea,b
		*Dronedarone a	*Itraconazolea,b	*Ketoconazolea,b
		*Ketoconazole a	*Ketoconazolea,b	*Posaconazolea,b
		Quinidine a	*Posaconazolea,b	* Ritonavira,b
		*Ticagrelor a	*Ritonavira,b	*Voriconazolea,b
		Verapamil a	*Voriconazolea,b
Pharmacokinetic	Decrease of at least 50% in anticoagulant plasma concentrations	*Carbamazepine c	*Carbamazepinec,d	*Carbamazepinec,d
		*Rifampin c	*Phenobarbitalc,d	*Phenobarbitalc,d
		*St. John’s wort c	*Phenytoinc,d	*Phenytoinc,d
			*Rifampinc,d	*Rifampinc,d
			*St. John’s wortc,d	*St. John’s wortc,d
Pharmacodynamic	Increased risk of bleeding	ASA	ASA	ASA
		NSAIDs	NSAIDs	NSAIDs
		Platelet aggregation inhibitors e	Platelet aggregation inhibitors e	Platelet aggregation inhibitors e
		*Anticoagulants f	*Anticoagulants f	*Anticoagulants f
		*Thrombolytics g	*Thrombolytics g	*Thrombolytics g

ASA, aspirin; NSAIDs, nonsteroidal anti-inflammatory agents.

*

Concomitant use is contraindicated or not recommended.

a

P-glycoprotein (P-gp) inhibition.

b

CYP 450 3A4 inhibition.

c

P-gp induction.

d

CYP 450 3A4 induction.

e

Platelet aggregation inhibitors include abciximab, clopidogrel, dipyridamole, eptifibatide, prasugrel, ticagrelor, ticlopidine and tirofiban.

f

Anticoagulants include argatroban, bivalirudin, danaparoid, fondaparinux, heparin, lepirudin, low-molecular-weight heparins (dalteparin, enoxaparin, nadroparin, tinzaparin) and warfarin. Note that when switching from one of the new oral anticoagulants to warfarin, a short period of concomitant use is acceptable to allow time to achieve therapeutic international normalized ratio.

g

Thrombolytics include alteplase, reteplase and tenecteplase.

Note: (above list of drug interactions is not exhaustive)

1) P-glycoprotein (P-gp) is a transporter system located in the epithelial cells of the intestine (enterocytes). As the drug molecules diffuse through the enterocytes, P-gp picks up the drug molecules and carries them back to the luminal side of the cell, preventing them from reaching the circulation. Therefore, when a drug inhibits the P-gp pump system, it increases the systemic availability of a P-gp–sensitive drug, with a resultant enhanced activity/toxicity. Conversely, if a drug induces the P-gp system, less of the drug reaches the systemic circulation and therefore its activity will be decreased.

2) CYP 450 3A4 is an enzyme located in the liver, which metabolizes a wide variety of drugs. Inhibition will decrease the metabolism of drugs that depend on this enzyme for their elimination, thereby increasing the activity/toxicity of these agents. Conversely, if a drug induces this enzyme, the drugs that depend on this enzyme for their elimination will have a higher rate of elimination and their activity will be diminished.