A Single-Dose Crossover Pharmacokinetic Comparison Study of Oral, Rectal and Topical Quetiapine in Healthy Adults

Current Updates in Rectal Infusion of Fluids and Medications

Purpose of Review

Rectal infusion is a feasible alternative for the immediate administration of medication and fluids when intravenous access is delayed, contraindicated, or unnecessary. Advances in medical device technology have made rectal infusion more practical and easier for medical care providers, and more comfortable for patients. This paper briefly reviews the history of therapeutic rectal infusion, including recent improvements in technology and the existing evidence for the use of this technique.

Recent Findings

While ultrasound-guided peripheral intravenous (PIV) access techniques and other alternatives to landmark-based PIV catheter insertion have recently improved the ability of providers to overcome challenges related to difficult vascular access (DVA), these challenges are increasingly affecting patient outcomes, emergency department throughput, and the cost of medical care. In recent years, waves of parenteral drug, fluid, and supply shortages have affected hospitals. Concurrently, advances in rectal infusion technology have made rectal infusion easier, more comfortable, and more cost-effective than many parenteral options.

Summary

The infusion of resuscitative fluids and medications via the rectal route has previously fallen out of favor due to concurrent improvements in IV access devices. However, this technique demonstrates the potential for a reemergence considering the current challenges facing healthcare providers and systems. Improvements in rectal infusion devices, coupled with an aging population, increased incidence of DVA, shortages in parenteral drugs, fluids, supplies and skilled staff, and the need for care improvements in the post-acute setting have contributed to a greater need for easy, safe and effective alternatives to IV infusion.

A Lack of Systemic Absorption Following the Repeated Application of Topical Quetiapine in Healthy Adults

In the absence of suitable oral or intravenous access for medication administration and when the intramuscular medications are undesirable, alternative routes for drug delivery may be considered. Antipsychotics administered via an inhaled, intranasal, rectal, or topical route have been described in the literature. Topically administered antipsychotics have been previously reported to produce negligible systemic absorption despite being used in clinical practice for nausea and behavioral symptoms associated with dementia. Additionally, the American Academy of Hospice and Palliative Medicine recommends against the use of topical medications that lack supporting literature. Three studies have assessed the systemic absorption of different antipsychotics after administration of only a single, topically applied dose. To evaluate whether the repeated administration of a topically applied antipsychotic may result in detectable serum levels in an accumulating fashion, a pharmacokinetic study was conducted. Five healthy, adult participants consented to receive extemporaneously prepared topical quetiapine in Lipoderm every 4 hours for a total of 5 doses. Blood samples were drawn at baseline and hours 2, 4, 8, 12, 16, and 24, and serum quetiapine concentrations were measured using high-performance liquid chromatography. Quetiapine was undetectable in every sample from 3 participants. Two participants had minimally detectable serum quetiapine levels no sooner than hour 12 of the study period. Extemporaneously prepared quetiapine in Lipoderm resulted in nonexistent or minimal serum level following repeated topical administration. The use of topically applied quetiapine should still be questioned.