Clinical pharmacology applications in clinical drug development and clinical care: A focus on Saudi Arabia

Drug development, from preclinical to clinical studies, is a lengthy and complex process. There is an increased interest in the Kingdom of Saudi Arabia (KSA) to promote innovation, research and local content including clinical trials (Phase I-IV). Currently, there are over 650 registered clinical trials in Saudi Arabia, and this number is expected to increase. An important part of drug development and clinical trials is to assure the safe and effective use of drugs. Clinical pharmacology plays a vital role in informed decision making during the drug development stage as it focuses on the effects of drugs in humans. Disciplines such as pharmacokinetics, pharmacodynamics and pharmacogenomics are components of clinical pharmacology. It is a growing discipline with a range of applications in all phases of drug development, including selecting optimal doses for Phase I, II and III studies, evaluating bioequivalence and biosimilar studies and designing clinical studies. Incorporating clinical pharmacology in research as well as in the requirements of regulatory agencies will improve the drug development process and accelerate the pipeline. Clinical pharmacology is also applied in direct patient care with the goal of personalizing treatment. Tools such as therapeutic drug monitoring, pharmacogenomics and model informed precision dosing are used to optimize dosing for patients at an individual level. In KSA, the science of clinical pharmacology is underutilized and we believe it is important to raise awareness and educate the scientific community and healthcare professionals in terms of its applications and potential. In this review paper, we provide an overview on the use and applications of clinical pharmacology in both drug development and clinical care.

Neonatal plastibell circumcision: does the thread type matter? a prospective randomized study

INTRODUCTION

Plastibell is one of the most common disposable devices used for circumcision. The study aims to determine whether changing the thread type from cotton to polypropylene to tie around the Plastibell in neonatal circumcision would result in faster separation of the ring.

PATIENTS AND METHODS

Prospective, randomized, clinical and biomechanical studies were performed. All circumcisions were performed by a single surgeon. Data collected included anthropometric measures, demographic data, procedure time, complications, parent satisfaction, follow-up, and outcomes. The biomechanical study measured the tensile properties of both threads using a universal testing machine (4465; Instron, Norwood, MA).

RESULTS

Two hundred full-term, male neonates aged between 24 and 48 h were circumcised using Plastibell. Both groups were similar in gestational age, age at circumcision, body weight, height, head circumference, Apgar score at 1 and 5 min, procedure time, Plastibell size, and parent satisfaction. The subjects were randomized into two groups of 100 neonates each: group I where Plastibell was tied by a cotton thread supplied by the manufacturer and group II where Plastibell was tied by Polypropylene 0. The mean duration for Plastibell fall-off was 8.98 days and 7.74 days in cotton thread and Polypropylene 0, respectively (P-value < 0.001). There was no difference regarding the complications for both groups. The diameters of the cotton and Polypropylene 0 threads were 0.68 mm and 0.35 mm, respectively. The measured tensile strengths of cotton and Polypropylene thread were 180 MPa and 457 MPa, respectively.

CONCLUSION

Plastibell tied by Polypropylene 0 fell off faster than that tied by cotton thread, with no significant differences in adverse effects or complications. This finding might be relevant for anxious parents and caregivers. Further studies are needed to examine other types and sizes of threads to investigate whether this separation period can be reduced further.

Melatonin vs. midazolam premedication in children: a double-blind, placebo-controlled study

BACKGROUND AND OBJECTIVE

Unlike midazolam, melatonin premedication is not associated with cognitive impairment in adults despite its anxiolytic properties. The use of melatonin as a premedicant in children has not been reported. This randomized, double-blind, placebo-controlled study compared the perioperative effects of different doses of melatonin and midazolam in children.

METHODS

Seven groups of children (n = 15 in each) were randomly assigned to receive one of the following premedicants. Midazolam 0.1, 0.25 or 0.5 mg kg(-1) orally, melatonin 0.1, 0.25 or 0.5 mg kg(-1) orally each mixed in 15 mg kg(-1) acetaminophen, or placebo only (15 mg kg(-1) acetaminophen). Anxiety and temperament were evaluated before and after administration of the study drug, on separation from parents and on the introduction of the anaesthesia mask. At week 2 postoperatively, the behaviour of the children was measured by the Post Hospitalization Behaviour Questionnaire.

RESULTS

Melatonin or midazolam each in doses of 0.25 or 0.5 mg kg(-1) were equally effective as premedicants in alleviating separation anxiety and anxiety associated with the introduction of the anaesthesia mask. A trend was noted for midazolam to prolong recovery times as the dosage increased. The use of melatonin was associated with a lower incidence (P = 0.049) of excitement at 10 min postoperatively, and a lower incidence (P = 0.046) of sleep disturbance at week 2 postoperatively than that observed with midazolam and control groups. No postoperative excitement was noted in the melatonin groups at 20, 30 and 45 min.

DISCUSSION

Melatonin was not only as effective as midazolam in alleviating preoperative anxiety in children, but it was also associated with a tendency towards faster recovery, lower incidence of excitement postoperatively and a lower incidence of sleep disturbance at week 2 postoperatively.

Contact allergy to 8-methoxypsoralen

A 36-year-old female patient was treated with PUVA for dyshidrotic eczema that had not shown sufficient response to topical therapy over the previous months. PUVA therapy caused acute aggravation of the eczema. Patch testing demonstrated Type IV sensitization to 8-methoxypsoralen in Meladinine solution.