Burden, Severity and Characteristic Pattern of Coronary Artery Disease using 160-Slice Computed Tomographic Angiography: Earliest Report from Northern Nigeria

BACKGROUND

Coronary computed tomography angiography (CCTA) allows for non-invasive visualization of the coronary arteries which is promising in diagnosing coronary artery disease.

OBJECTIVES

To determine the prevalence, morphology, anatomic distribution pattern and correlates of CAD in our environment.

METHODS

This cross-sectional study was conducted on the first cohort of patients referred for CCTA in our hospital. The patients were examined with 160-slice Toshiba® CT scanner. Their demographic data, relevant clinical information as well as the findings on CCTA were extracted and documented. The data were analysed using the R programming software version 4.0.4.

RESULTS

Out of a total of 153 patients who presented for CCTA within the study period, 133 (84.7%) were eligible for analysis. Their age ranged from 22-78 years with a mean ± SD of 55.8 ± 11.7 years. A total of 33 (24.8%) had normal CCTA, while 100 (75.2%) had either stenosis or total occlusion. There was a significantly higher (p-value of 0.00001) calcium score among those with stenosis compared to those with normal CCTA. The severity of the stenotic lesion was associated with the calcium score. The logistic regression analyses showed a statistically significant (P = 0.0415, OR = 1.0569, 97.5% CI =1.078152-1.123240) association between age and the presence of coronary stenosis. In addition, most of the stenotic lesions were in the left anterior descending artery (LAD).

CONCLUSION

Majority of the patients had coronary artery disease of variable severity and the LAD was the most involved artery. There was no significant association between sex and severity of the disease; however, old age and higher number of lesions were associated with severe disease.

Pharmacokinetics of celecoxib after oral administration in dogs and humans: effect of food and site of absorption

Celecoxib pharmacokinetics was evaluated after single and multiple oral dosing; after dosing in a solution and as a solid; with and without food; and after administration into different sites of the GI tract using dog. After oral dosing in a solution, celecoxib was rapidly absorbed and reached maximum concentrations by 1 h; absorption was delayed another 1 to 2 h when administered as a solid. The absolute bioavailability of celecoxib was higher when given as a solution (64--88%) compared with capsule (22--40%). The absorption of celecoxib given in a capsule was delayed by food, although systemic exposure increased by 3- to 5-fold. The systemic availability of celecoxib given intragastrically in solution was similar to that obtained following direct instillation into the duodenum, jejunum, or colon through a chronic intestinal access port. Collectively, these data suggest that celecoxib is a highly permeable drug that can be absorbed throughout the GI tract and that dissolution may be a rate-limiting factor for absorption from solid dosage forms. Unlike dogs, celecoxib given to humans with a high fat meal exhibits only a slight increase in AUC(0--infinity) (11%) that is not clinically significant with regard to safety or efficacy. In humans, a lower dose and a longer GI residence time may promote the opportunity for absorption of a poorly soluble drug such as celecoxib that can be absorbed throughout the GI tract. This would minimize the effect of food on absorption; as such, patients with arthritis can be given celecoxib with or without food.

Comparison of celecoxib metabolism and excretion in mouse, rabbit, dog, cynomolgus monkey and rhesus monkey

1. The metabolism and excretion of celecoxib, a specific cyclooxygenase 2 (COX-2) inhibitor, was investigated in mouse, rabbit, the EM (extensive) and PM (poor metabolizer) dog, and rhesus and cynomolgus monkey. 2. Some sex and species differences were evident in the disposition of celecoxib. After intravenous (i.v.) administration of [14C]celecoxib, the major route of excretion of radioactivity in all species studied was via the faeces: EM dog (80.0%), PM dog (83.4%), cynomolgus monkey (63.5%), rhesus monkey (83.1%). After oral administration, faeces were the primary route of excretion in rabbit (72.2%) and the male mouse (71.1%), with the remainder of the dose excreted in the urine. After oral administration of [14C]celecoxib to the female mouse, radioactivity was eliminated equally in urine (45.7%) and faeces (46.7%). 3. Biotransformation of celecoxib occurs primarily by oxidation of the aromatic methyl group to form a hydroxymethyl metabolite, which is further oxidized to the carboxylic acid analogue. 4. An additional phase I metabolite (phenyl ring hydroxylation) and a glucuronide conjugate of the carboxylic acid metabolite was produced by rabbit. 5. The major excretion product in urine and faeces of mouse, rabbit, dog and monkey was the carboxylic acid metabolite of celecoxib.