Drug administration via feeding tubes-a procedure that carries risks: systematic identification of critical factors based on commonly administered drugs in a cohort of stroke patients

PURPOSE

Drug administration via feeding tubes is considered a process with many uncertainties. This review aimed to give a comprehensive overview of data available on feeding tube application and to carry out risk assessments for drug substances commonly administered to stroke patients.

METHODS

Drugs frequently administered via feeding tubes were identified through a retrospective analysis of discharge letters from a stroke unit. Physicochemical, pharmacokinetic, and stability properties of these drugs and data on drug-enteral nutrition interactions were systematically searched for in the European Pharmacopoeia, Hagers Handbook of Pharmaceutical Practice, Birchers clinical-pharmacological data compilation, and the Martindale Complete Drug Reference, as well as from databases including DrugBank, DrugDex, PubChem, Google Scholar, and PubMed.

RESULTS

Of the drugs most commonly administered via feeding tubes in the present stroke patient cohort, bisoprolol, candesartan, and ramipril could be considered the least critical due to their overall favourable properties. Acetylsalicylic acid, amlodipine, hydrochlorothiazide, omeprazole and esomeprazole, simvastatin, and torasemide pose risks based on pH or light-dependent instability or proposed food effects. The most critical drugs to be administered via feeding tubes are considered to be furosemide, levodopa, and levothyroxine as they show relevant instabilities under administration conditions and substantial food effects; the latter two even possess a narrow therapeutic index. However, little information is available on drug-tube and drug-formula interactions.

CONCLUSION

Feeding tube administration of medications turned out to be a highly complex process with several unmet risks. Therefore, investigations that systematically assess these risk factors using clinically relevant model systems are urgently needed.

A Pilot Randomized Controlled Trial Comparing Levothyroxine to Placebo in Neurologically Deceased Donors

BACKGROUND

Although commonly prescribed, the efficacy of levothyroxine to improve heart function in neurologically deceased donors is unclear. We evaluated the feasibility of a randomized controlled trial to compare levothyroxine to placebo on the variation of left ventricular ejection fraction, in hemodynamically unstable donors.

METHODS

We conducted a pilot, double-blinded, randomized controlled trial. Deceased donors with reduced left ventricular ejection fraction or needing vasopressors were included. We randomized participants to a 20 μg bolus followed by a 20 μg/h infusion of levothyroxine or an identically appearing placebo. We report the proportion of recruited participants, the time to the administration of the study drug, and protocol violations.

RESULTS

Twenty-four participants (N = 24/104; 23.1%) were eligible. Five of them (N = 5/24; 20.8%) were excluded by the attending physician. Four others were not included, due to family refusal for research (n = 2/24;8.3%) and unavailability of research staff (n = 2/24; 8.3%). Fifteen participants were randomized (N = 15/104; 14.4%). Mean time between the echocardiography and the initiation of the drug was 1.73 hours, and14 (93.3%) of 15 of the participants received the drug within 2 hours after the echocardiography. We report no study violation. The study was stopped prematurely because of low recruitment.

CONCLUSION

This pilot trial suggests that the success of a definitive randomized control trial to assess the efficacy of levothyroxine in deceased donors could benefit from a multicenter recruitment and education on the evidence surrounding the pharmacological management of organ donors. The need for consent to research interventions in deceased donors should also be clarified.

Thyroid hormone (levothyroxine) replacement via the respiratory route by inhalation: in vitro exploratory studies

OBJECTIVES

To conduct proof of principle studies that will enable development of noninvasive (respiratory) delivery systems for levothyroxine (T4).

METHODS

Preformulation (solubility, stability), formulation and biopharmaceutical (in vitro absorption, transport, gene expression) studies were conducted. Calu-3 cell line was used for permeation studies.

RESULTS

Solubility profiles of T4 were established in aqueous (PBS, HBSS, isotonic saline) and non-aqueous solvents (PEG 400, PEG 600, propylene glycol, glycerine). Transport of the compound across Calu-3 cells suggested involvement of active transport systems. This correlated with expression of thyroxine transporters (MCT8, MCT10, OATP1A2, LAT1 and LAT2) in the cell line. Diffusion characteristics showed significant absorption with no detection of T4 metabolite (triiodothyronine). Formulation studies revealed that stable formulations could be prepared using a combination of aqueous and non-aqueous solvents.

CONCLUSIONS

Results of the studies indicated that T4 can be absorbed effectively from the respiratory mucosa. Factors affecting stability such as pH and temperature should be taken into account during formulation development of this compound for the respiratory route.