The Effects of Charcoal and Sorbitol (Alone and in Combination) on Plasma Theophylline Concentrations after a Sustained-Release Formulation

1990 ◽  
Vol 9 (3) ◽  
pp. 179-182 ◽  
Author(s):  
A.H. Al-Shareef ◽  
D.C. Buss ◽  
E.M. Allen ◽  
P.A. Routledge

1 The effects of charcoal and sorbitol, alone and in combination, were investigated in eight healthy female volunteers who received 600 mg slow-release theophylline (two 300 mg capsules) . 2 The area under the plasma concentration time curve to 24 h (AUC0-24) after theophylline alone was significantly greater than after both the charcoal and charcoal plus sorbitol phase. 3 Charcoal and charcoal with sorbitol also significantly reduced the maximum plasma theophylline concentration ( Tmax) and time to maximum concentration ( Cmax). 4 Sorbitol significantly increased Cmax and shortened Tmax. 5 Although sorbitol did not reduce the adsorptive efficacy of charcoal, its use alone may be deleterious in poisoning with sustained-release theophylline products.

1996 ◽  
Vol 24 (4) ◽  
pp. 331-339 ◽  
Author(s):  
G Tatsis ◽  
G Tsoukalas ◽  
A Haviaras ◽  
A Peristerakis ◽  
V Filaditaki ◽  
...  

The bioavailability of a new sustained-release anhydrous theophylline product (Theophylline Lavipharm®) was evaluated and compared with the bioavailability of a well-established product, Theodur®. Two groups of 12 healthy non-smokers were given single doses of 200 or 300 mg of each product and two groups of 12 patients with asthma or chronic obstructive lung disease were given doses of 200 or 300 mg of each product every 12 h for 5-day periods. The values of the area under the plasma theophylline concentration against time curve (AUC), the maximum plasma theophylline concentration ( Cmax) and the time taken to reach Cmax (Tmax) for the two products did not differ significantly in the healthy groups or in the patients. The minimum and the average plasma theophylline concentrations and the fluctuation index were also calculated for the patients and there were no significant differences between the values for the two products. The new anhydrous theophylline product, Theophylline Lavipharm®, appears to show very similar bioavailability to Theodur®. No adverse reactions to the new product were reported.


1987 ◽  
Vol 15 (6) ◽  
pp. 352-360
Author(s):  
S. Giosue' ◽  
D Bernocchi ◽  
D. Parola ◽  
R. Munno ◽  
P. Mancini

A sustained-release theophylline preparation in capsule form was compared with standard slow-release theophylline tablets for variation in plasma theophylline concentration, effectiveness and tolerability in 30 adults with chronic broncho-obstructive pathology. They were administered every 12 h and blood samples were collected after 8 days of treatment during the steady-state period. In this double-dummy crossover study, the sequence of the two regimens (sustained-release capsules versus tablets) was selected at random. The results of this study demonstrate that plasma theophylline levels remain within the therapeutic range for both preparations. Effectiveness and tolerability of the two drugs were satisfactory.


2021 ◽  
Vol 134 (1) ◽  
pp. 95-101 ◽  
Author(s):  
R. Loch Macdonald ◽  
Daniel Hänggi ◽  
Poul Strange ◽  
Hans Jakob Steiger ◽  
J Mocco ◽  
...  

OBJECTIVEThe objective of this study was to measure the concentration of nimodipine in CSF and plasma after intraventricular injection of a sustained-release formulation of nimodipine (EG-1962) in patients with aneurysmal subarachnoid hemorrhage (SAH).METHODSPatients with SAH repaired by clip placement or coil embolization were randomized to EG-1962 or oral nimodipine. Patients were classified as grade 2–4 on the World Federation of Neurosurgical Societies grading scale for SAH and had an external ventricular drain inserted as part of their standard of care. Cohorts of 12 patients received 100–1200 mg of EG-1962 as a single intraventricular injection (9 per cohort) or they remained on oral nimodipine (3 per cohort). Plasma and CSF were collected from each patient for measurement of nimodipine concentrations and calculation of maximum plasma and CSF concentration, area under the concentration-time curve from day 0 to 14, and steady-state concentration.RESULTSFifty-four patients in North America were randomized to EG-1962 and 18 to oral nimodipine. Plasma concentrations increased with escalating doses of EG-1962, remained stable for 14 to 21 days, and were detectable at day 30. Plasma concentrations in the oral nimodipine group were more variable than for EG-1962 and were approximately equal to those occurring at the EG-1962 800-mg dose. CSF concentrations of nimodipine in the EG-1962 groups were 2–3 orders of magnitude higher than in the oral nimodipine group, in which nimodipine was only detected at low concentrations in 10% (21/213) of samples. In the EG-1962 groups, CSF nimodipine concentrations were 1000 times higher than plasma concentrations.CONCLUSIONSPlasma concentrations of nimodipine similar to those achieved with oral nimodipine and lasting for 21 days could be achieved after a single intraventricular injection of EG-1962. The CSF concentrations from EG-1962, however, were at least 2 orders of magnitude higher than those with oral nimodipine. These results supported a phase 3 study that demonstrated a favorable safety profile for EG-1962 but yielded inconclusive efficacy results due to notable differences in clinical outcome based on baseline disease severity.Clinical trial registration no.: NCT01893190 (ClinicalTrials.gov).


1985 ◽  
Vol 23 (11) ◽  
pp. 43-44

Piretanide is a loop diuretic recently marketed in a sustained-release formulation (Arelix - Hoechst) solely for the treatment of hypertension (rather than as a general diuretic). The manufacturer claims that piretanide has several advantages over the thiazides, including little or no effect on plasma potassium and magnesium, and no impairment of glucose tolerance.


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