Drugs for hypertension

American College of Cardiology/American Heart Association (ACC/AHA) guidelines for treatment of hypertension were last published in 2018.1 Treatment of hypertensive urgencies and emergencies is not discussed here.

Binder jetting 3D printing of challenging medicines: from low dose tablets to hydrophobic molecules

Increasing access to additive manufacturing technologies utilising easily available desktop devices opened novel ways for formulation of personalized medicines. It is, however, challenging to propose a flexible and robust formulation platform which can be used for fabrication of tailored solid dosage forms composed of APIs with different properties (e.g., hydrophobicity) without extensive optimization. This manuscript presents a strategy for formulation of fast dissolving tablets using binder jetting (BJ) technology. The approach is demonstrated using two model APIs: hydrophilic quinapril hydrochloride (QHCl, logP = 1.4) and hydrophobic clotrimazole (CLO, logP = 5.4). The proposed printing method uses inexpensive well known and easily available FDA approved pharmaceutical excipients. The obtained model tablets had uniform content of the drug, excellent mechanical properties and highly porous structure resulting in short disintegration time and fast dissolution rate. The tablets could be scaled and obtained in predesigned shapes and sizes. The proposed method may find its application in the early stages of drug development where high flexibility of the formulation is required and the amount of available API is limited.

[Comparative Efficacy of the Influence of Fixed Combinations of Antihypertensive Drugs That Block the Renin-Angiotensin-Aldosterone System, With Thiazide Diuretics on the Parameters of Ambulatory Blood Pressure Monitoring]

AIM

to compare effects of fixed-dose combinations of antihypertensive drugs that block renin-angiotensin-aldosterone system (RAAS) with hydrochlorothiazide (HCT) on parameters of ambulatory blood pressure monitoring (ABPM).

MATERIAL AND METHODS

Patients (n=50; 25 women, 25 men aged 40-75 years) with stage II essential hypertension who received no antihypertensive therapy for 12 weeks were randomized to receive once daily fixed-dose combinations of either valsartan/HCT (Val/HCT - group I) or quinapril/HCT (Quin/HCT - groupII) in starting doses of 80/12.5 or 10/12.5 mg, respectively. If target BP (<140 and 90 mm Hg) was not achieved after 2 weeks, doses were increased to 160/12.5 and 20/12.5 mg, respectively. Patients in whom target BP was not achieved after another 2 weeks were excluded from the study. Follow - up after achieving target BP was 12 weeks.

RESULTS

Both combinations significantly (p<0.001) reduced office systolic and diastolic BP (SBP and DBP), however, BP decrease in group I was significantly (p<0.01) greater (-42.0+/-2,7 /-22.2+/-1.2 mm Hg) than in group II (-26,4+/-2,1/-6.6+/-0.4 mm Hg). Significant reduction of day- and night-time BP (p<0.001) observed in both groups was also more pronounced (p<0.01) in group I. In both groups we recorded significant (p<0.01) decreases of BP variability and morning BP rise. Variability of DBP at night (-3.3+/-0.2 mm Hg), magnitude and speed of morning DBP surge (-20.9+/-0.3 mm Hg and -3.4+/-0.2 mm Hg/hour, respectively) in group I decreased significantly (p<0.05) greater compared with same parameters in group II (-2.5+/-0.2 mm Hg, -17.7+/-0.3 mm Hg, -2.6+/-0.2 mm Hg/hour, respectively).

CONCLUSION

Fixed-dose combinations of RAAS blockers and HCT provided reliable reduction of BP, BP variability, morning BP rise, and high percentage of achievement of target BP. Val/HCT combination was more effective in terms of reducing SBP, DBP and pulse BP levels at routine measurement, and day- and night-time SBP and DBP, night-time DBP variability, and rate of morning DBP rise.

Effect of carboxylesterase 1 c.428G > A single nucleotide variation on the pharmacokinetics of quinapril and enalapril

AIM

The aim of the present study was to investigate the effects of the carboxylesterase 1 (CES1) c.428G > A (p.G143E, rs71647871) single nucleotide variation (SNV) on the pharmacokinetics of quinapril and enalapril in a prospective genotype panel study in healthy volunteers.

METHODS

In a fixed-order crossover study, 10 healthy volunteers with the CES1 c.428G/A genotype and 12 with the c.428G/G genotype ingested a single 10 mg dose of quinapril and enalapril with a washout period of at least 1 week. Plasma concentrations of quinapril and quinaprilat were measured for up to 24 h and those of enalapril and enalaprilat for up to 48 h. Their excretion into the urine was measured from 0 h to 12 h.

RESULTS

The area under the plasma concentration-time curve from 0 h to infinity (AUC0-∞) of active enalaprilat was 20% lower in subjects with the CES1 c.428G/A genotype than in those with the c.428G/G genotype (95% confidence interval of geometric mean ratio 0.64, 1.00; P = 0.049). The amount of enalaprilat excreted into the urine was 35% smaller in subjects with the CES1 c.428G/A genotype than in those with the c.428G/G genotype (P = 0.044). The CES1 genotype had no significant effect on the enalaprilat to enalapril AUC0-∞ ratio or on any other pharmacokinetic or pharmacodynamic parameters of enalapril or enalaprilat. The CES1 genotype had no significant effect on the pharmacokinetic or pharmacodynamic parameters of quinapril.

CONCLUSIONS

The CES1 c.428G > A SNV decreased enalaprilat concentrations, probably by reducing the hydrolysis of enalapril, but had no observable effect on the pharmacokinetics of quinapril.

Quinapril and its metabolite quinaprilat in human milk

AIMS

To measure the milk to plasma ratio (M/P) of quinapril and its active metabolite quinaprilat in lactating mothers and to assess likely infant exposure.

METHODS

A single dose of quinapril 20 mg was administered to six healthy mothers who had been breastfeeding their infants for at least 2 weeks. Blood was sampled for the measurement of quinapril and quinaprilat at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 16 and 24 h. Milk was collected for measurement of quinapril and quinaprilat concentrations over the periods -4-0, 0-4, 4-8, 8-12, 12-18, 18-24 h. The areas under the plasma and milk concentration-time curves were estimated and an M/P ratio derived for both quinapril and quinaprilat.

RESULTS

The M/P ratio for quinapril was 0.12 (95% CI 0.09,0.14). No quinapril was detected in milk after 4 h. No quinaprilat was detected in any of the milk samples. The estimated 'dose' of quinapril that would be received by the infant was 1.6% (95% CI 1.0,2.2) of the maternal dose, adjusted for respective weights.

CONCLUSIONS

Quinapril appears to be 'safe' during breastfeeding according to conventional criteria, although as always, the risk:benefit ratio should be considered when it is to be given to a nursing mother.

Heart failure development in rats with ascending aortic constriction and angiotensin-converting enzyme inhibition

It remains unknown whether angiotensin-converting enzyme (ACE) inhibition can prevent heart failure in rats with a fixed high pressure load of the left ventricle and if this effect could be attributed to normalization of contractile protein phenotype and cardiac collagen content. Rats with constriction of the ascending aorta were treated with the ACE inhibitor quinapril (6 mg kg(-1) day(-1)) (n=95) or placebo (n=96) (starting 6 weeks post surgery. Quinapril treatment improved survival markedly (P<0.0000001) during the 24 weeks observation period. There were 69 deaths with placebo and only 25 deaths with quinapril. At the end of the observation period signs of left ventricular backward failure were, however, detected in 75 rats with placebo and in 67 rats treated with quinapril (P=0.229). Cox proportional hazard model with time-dependent covariates was used to document that the effect of quinapril treatment had been dependent on time. Quinapril had no significant effect on the development of morphological signs of left ventricular dysfunction after the first 54 days of treatment. The increased isomysin V(3) proportion of hypertrophied non-failing hearts was also not affected by quinapril treatment. Irrespective of treatment, failing hypertrophied hearts were characterized by an increase in left ventricular volume (P<0.05), percentage of the 'foetal' isomyosin V(3) (P<0.05), and hydroxyproline concentration (P<0.05). While the cause of the improved survival remains unknown, quinapril did apparently not interfere with the restitution of 'foetal' gene expression of pressure overloaded cardiomyocytes leading to depressed myocardial performance, ventricular dysfunction and the consecutive myocardial fibrosis.

Attenuation by ACE inhibitor drugs of alpha-adrenoceptor sensitivity in human vessels: possible differences related to drug lipophilicity

AIMS

We investigated the effect of angiotensin converting enzyme inhibitors (ACEIs) on postsynaptic adrenoceptor sensitivity and compared the effect of the lipophilic ACEI, quinapril, and that of hydrophilic agent, enalapril in human vessels.

METHODS

Alpha-adrenoceptor sensitivity was evaluated using the dorsal hand vein compliance technique. The dose-response curves of vasoconstriction to phenylephrine and prostaglandin F2alpha were obtained in healthy male volunteers.

RESULTS

The ACEIs shifted the dose-response curve of phenylephrine to the right and raised the median effective dose (ED50; 189.3 (57.6 ng min(-1)) of phenylephrine. Following quinapril administration, ED50 increased to 481.1 (101.8 ngmin(-1) compared with 266.8 (55.8 ngmin(-1) after enalapril (95% CI for differences; 31.1-397.5 ng min(-1)). Quinapril administration had no effect on the dose-response curve of PGF2alpha.

CONCLUSIONS

ACE inhibition attenuates alpha-adrenoceptor sensitivity in human vessels. The effect of quinapril, a lipophilic ACEI, was greater than that of enalapril, a hydrophilic ACEI. Lipophilic ACEIs may be more potent in vasodilating effect than hydrophilic ACEIs. Angiotensin II concentration in tissue rather than that in plasma may contribute to the alpha-adrenoceptor sensitivity of the vessels.