The effect of temazepam on respiration in elderly insomniacs with mild sleep apnea

This study evaluated the respiratory effect of temazepam in elderly subjects (mean age 65 +/- 3.8 years), with mild sleep apnea. The 15 subjects of this report were enrolled in a larger randomized trial comparing pharmacological and behavioral treatments for insomnia. Seven subjects received temazepam 15-30 mg/day either alone or in combination with behavior therapy, and eight subjects received placebo or behavior therapy. The mean baseline respiratory disturbance index (RDI) was 9.2 +/- 2.8 for the nondrug and 8.8 +/- 5.3 for the temazepam group. There were no significant time, group or interaction effects. There was no increase in the RDI in elderly subjects with mild respiratory apnea receiving 15-30 mg of temazepam.

Effect of autonomic blockade on heart rate and blood pressure in sleep apnea syndrome

To determine the impact of the autonomic nervous system on hemodynamic responses to sleep apnea we studied 7 male patients (48 +/- 6 years, BMI = 29.7 +/- 2.9 kg/m2) with an apnea index = 33 + 11/h. In two hypertensives, therapy was withdrawn 2 weeks before the study. During a full night polysomnography EEG, EOG, EMG, respiration, oximetry, heart rate (HR) and blood pressure (BP) (Finapres 23OOE) were recorded. Placebo and 3 short-acting autonomic blockers were randomly i.v. administered: antimuscarinic (atropine 1 mg, A), beta 1 blocker (esmolol 40 mg, E), alpha blocker (nicergoline 2.5 mg, N). A total of 367 obstructive apneas in NREM sleep were studied. With atropine, HR was increased at the beginning of apnea (P1)(74.5 +/- 2 bpm vs 65.4 +/- 2 bpm with placebo) and at the end apnea (P3) (76.6 +/- 1.9 bpm vs 67.1 +/- 1.76 bpm). At the resumption of breathing (RB), HR still increased (83.5 +/- 1.5 bpm vs 80.1 +/- bpm). Nicergoline had no significant effect on HR but significantly decreased SBP (117.8 +/- 1.4 mmHg vs 127 +/- 1.6 with placebo, p < 0.001). Nevertheless, the rise in BP from P3 to RB remained significant (p < 0.001). Esmolol significantly decreased HR at P1 (68.1 +/- 1.9 bpm vs 73.9 +/- 1.9 bpm) and at RB (75.9 +/- 1.9 vs 81.6 +/- 1.8). With A, the rise in HR at end-apnea (P3) suggests a vagal hyperactivity during this phase which is blunted at resumption when HR is unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacologic treatment of obstructive sleep apnea

From this review it is obvious that no one pharmacologic agent is universally useful in the treatment of OSA. However, as mentioned in the introductory remarks above, the expectation of beneficial results in a heterogenous population of patients with OSA by specific-acting pharmacologic agents may be somewhat irrational. In addition to this problem, studies performed to date are often not controlled and are usually investigations in small numbers of subjects. However, from the data produced it is apparent that OSA precipitated by endocrinologic problems will improve with hormone replacement. Medroxyprogesterone has been shown to be especially useful in patients with an obesity-hypoventilation component to their disease. Protriptyline may also be useful, but its usefulness is impaired by significant adverse effects. Most likely, both medroxyprogesterone and protriptyline would be more tolerable in female OSA patients, but unfortunately, most of the OSA patient groups studied to date have been composed exclusively of male subjects. Therefore, we do not know if these agents would be more effective and better tolerated in female patients with OSA. The roles of ACE inhibitors and buspirone are not yet established. Serotonin-active agents may be useful in some patients with OSA, but the characteristics of responders are not defined for appropriate patient selection. Much work remains ahead to identify effective pharmacologic agents for OSA. Once identified, these agents must be tested in representative patient groups with a double-blind, placebo-controlled study design in multicenter trials to test the value of these agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine analogues modulate the incidence of sleep apneas in rats

The effects of adenosine A1 and A2 agonists on spontaneous central sleep apneas in rats have been examined by simultaneously monitoring sleep and respiration in freely moving unanesthetized animals. Intraperitoneal administration of 1.0 mg/kg of the A1 receptor agonist R(-)N6-L-(2-phenyl-isopropyl)adenosine (L-PIA) and 150 and 300 micrograms/kg of 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamido-adenosine hydrochloride (CGS 21680), a selective A2 agonist, decreased the apnea index (AI) during sleep. Within a sleep period, AI increased over time in both control and drug-treated animals. For both agonists, doses effective in reducing AI also significantly reduced sleep efficiency.

Changes in phrenic, hypoglossal and recurrent laryngeal nerve activities after intravenous infusions of aminophylline in cats

Aminophylline is known to have respiratory stimulant properties, and it has been suggested that it may also be effective in sleep apnoea. However, its role in this disorder remains uncertain. Theoretically, increasing upper airway motoneural activity in order to maintain airway patency might alleviate obstructive sleep apnoea. On the other hand, increasing the respiratory drive may also prove beneficial in treating central sleep apnoea. In these studies, we attempted to determine the effect of aminophylline on neural activities of the upper airway and diaphragm. We administered intravenously either a low dose (4 mg.kg-1) or a high dose (16 mg.kg-1) of aminophylline to decerebrated, vagotomized and paralysed cats, and continuously recorded the phrenic hypoglossal and recurrent laryngeal nerve activities for 3 h. Results showed that a high dose of aminophylline induced a marked increase in phrenic nerve activity, but not hypoglossal or recurrent laryngeal nerve activity. In a group treated with a low dosage of aminophylline, a significant increase of activity was found in all three nerves. Furthermore, phrenic nerve activity increased more with a high dose than with a low dose. We confirmed that aminophylline has dose-dependent and selective effects on respiratory neural activity. A low dose acts on the upper airway and diaphragm, but a high dose induces a marked increase in central respiratory drive. According to our results, low dose aminophylline might be beneficial in obstructive sleep apnoea, whereas, a high or low dose might improve some cases of central sleep apnoea.

[Nicotine as therapy of obstructive sleep apnea?]

In 8 smokers (age 57 +/- 6 years, BMI 26.4 +/- 3.8 kg/m2) with an apnea-hypopnea index of 22.2 +/- 19.5 and who wanted to give up smoking with the help of nicotine plaster, various characteristic values of respiratory disturbances (among others, average and longest duration of various apnea and hypopnea, average and minimum oxygen saturation) were investigated during nicotine and control nights. All characteristic values, with the exception of the average oxygen saturation (from 93.7 to 94.4%, p < 0.02), did not change significant. These results indicate that nicotine could be an effective drug. However, it cannot yet be recommended for the treatment of obstructive sleep apnea because of some still unanswered questions (efficacy for non-smokers, side-effects, risk of addiction).

[Theophylline acceptance in long-term therapy of patients with obstructive sleep related respiratory disorder]

In 1,150 patients with sleep apnea syndrome, the apnea number, the morning theophyllin level, the symptom of morning exhaustion were recorded for the first night of theophyllin therapy and in the follow-up period of up to 5 years; in addition, side effects were noted at the end of the observation period. Prior to start of the therapy, the average apnea number was 97 per night; this decreased to 25 per night in the initial therapy. In the observation period of between 3 and 28 months, the number of apnea phases increased slightly on average. The symptoms of morning exhaustion initially decreased to 60% but increased again by about 20% over the next five years. In responders, theophyllin reduces the number of apnea in the long term course; however, frequent therapy controls are needed to determine the optimal dosage. Longitudinally, patients with an apnea index < 20/profited most from this drug therapy.

[Nocturnal hypertension and sleep apnea: effect of the ACE inhibitor cilazapril on apnea-induced blood pressure increases during sleep]

The nocturnal increases in blood pressure in cases of obstructive sleep apnea are discussed as causes in connection with increased cardiovascular mortality in sleep apnea. Previous antihypertension therapy studies revealed the antihypertensive action of the ACE inhibitor cilazapril averaged over NREM (NR) and REM sleep (R). In the present study, the effect of this drug on the blood pressure increase within the stress segment of obstructive apnea in NR and R was investigated in a double-blind randomized study versus placebo. Data were collected in digital form with the help of cardiorespiratory polysomnography and intra-arterial blood pressure measurements; a total of 640 apnea in 16 patients were evaluated. Relevant increases in blood pressure occurred during the apnea which were, as expected, more pronounced in R (150/74 mmHg) than in NR (135/69 mmHg). The antihypertensive action of cilazapril was also stronger in R (systole--11.9/diastole--6.4 mmHg) than in NR (systolic--9.0 mmHg/diastolic--5.7 mmHg). Placebo caused significantly lower decreases in blood pressure (systolic--3.7 mmHg/diastolic--2.4 mmHg in R, systolic--2.8 mmHg/diastolic--1.8 mmHg in NR). Thus, evidence is provided for a clinically relevant blood pressure lowering effect of the drug cilazapril on the stress-induced blood pressure increases accompanying obstructive apnea both in NREM and in REM sleep.

Effects of acetazolamide on the sleep apnea syndrome and its therapeutic mechanism

Twenty male patients with sleep apnea syndrome were treated with acetazolamide (AZM), a carbonic anhydrase inhibitor. In 14 of the patient a significant decrease was found in the number of apnea, apnea index and % apnea time (percentage of time spent with apnea to the total sleep time) with improvement in sleep structure, clinical symptoms, such as insomnia, daytime excessive sleepiness and snoring. A significant decrease was also observed in arterial blood pH and HCO-3 in the 14 improved patients. On the other hand, no improvement occurred in the parameters of sleep apnea and sleep with AZM in the remaining six patients. Moreover, metabolic acidosis and an improvement in arterial blood gases did not occur with AZM in the six patients.

[Organic psychosyndrome and sleep apnea. Transdermal nicotine--a new therapy concept?]

We examined 11 patients (10 female, 1 male) of 73 to 79 years of age suffering from organic psychosyndrome (HOPS), using the apnoea screen system MESAM IV (1) and APNOE-SCREEN I. All examined patients had a sleep related disordered breathing (SBAS) with apnoea index (AI) between 10 and 52 (P/h). 3 patients (2 female, 1 male) had an increasing apnoea index under medication of theophyllin 375 mg/d. these theophyllin-nonresponsive patients received transdermal Nicotin in a concentration of 21 mg/d (during the night). The apnoea index decreased not significantly, while the tiredness was reduced significantly by 42.9%, the confusion by 40% and the nightly restlessness by 50%.

Triazolam in patients with obstructive sleep apnea

The purpose of this study was to assess the effect of triazolam (0.25 mg) on apnea duration and the arousal response to airway occlusion during sleep in patients with severe obstructive sleep apnea (OSA). Twelve male subjects with a mean (+/- SD) age of 46.6 +/- 14.1 yr and body weight of 260.8 +/- 55.9 lb were studied on two nights separated by a nonstudy night. They ingested triazolam (0.25 mg) or placebo 0.5 h before bedtime in a randomized double-blind crossover manner. In non-rapid-eye-movement (NREM) sleep, the mean (+/- SEM) duration of apnea/hypopnea was slightly increased (26.8 +/- 1.7 versus 23.8 +/- 1.2 s, p < 0.02) and the mean nadir in arterial oxygen saturation lower (80.1 +/- 1.9 versus 84.2 +/- 1.4%, p < 0.001) on triazolam nights. In NREM sleep, the deflections in esophageal pressure prior to apnea termination were higher on triazolam nights (53.3 +/- 5.4 versus 44.5 +/- 4.8 cm H2O, p < 0.001). However, the rate of increase in inspiratory effort (esophageal pressure deflections) during obstructive events was not decreased by triazolam. We conclude that triazolam increases the arousal threshold to airway occlusion, but that this results in only modest prolongation of event duration and increased desaturation at a dose of 0.25 mg in a group of large sleep apnea patients.

Central apnea index decreases after prolonged treatment with acetazolamide

Only a limited number of studies dealing with the epidemiology and therapy of central sleep apnea syndrome (CA) are available. The treatment strategies are poorly defined and not well evaluated. The aim of our present study was to treat selected CA patients with low dose acetazolamide (ACET) for a longer time period than has been done before. Previous studies were performed with high dose ACET provoking severe metabolic acidosis, not for more than 1 wk or only in obstructive apnea patients. Referred patients with suspicion of sleep-related breathing disorders (SRBD) were included in the study if, after a first selection night, their central apnea index (CAI) was > 5 or their apnea-hypopnea index (AHI) > 10 and their obstructive apnea index (OAI) < 5. Of 327 screened patients, 14 (4.3%) fulfilled these criteria. Patients were then treated with ACET (250 mg, 1 h before sleep): Polysomnography was repeated once after one single dose (N2) and twice after 1-mo chronic treatment without (N3) and with (N4) additional ACET administration. After each study night, arterial blood gases and chemical drive were measured. CAI (25.5 +/- 6.8 at N1) already decreased during N2 (13.8 +/- 5.2) and further during N3 (6.6 +/- 2.9) and N4 (6.8 +/- 2.8) p < 0.01). OAI remained unchanged. Total sleep time (TST) and sleep efficiency index (SEI) did not change significantly. The number of arousals decreased from 62 +/- 11 at N1 to 40 +/- 5 at N3 (p = 0.019).(ABSTRACT TRUNCATED AT 250 WORDS)

Enuresis in an adult female with obstructive sleep apnea

Adult onset enuresis accompanied by obstructive sleep apnea has been reported rarely. A female patient was referred to our clinic with complaints of of a 15-year history of loud snoring and sleep apnea as well as enuresis, which was treated successfully with imipramine and acetazolamide. The mechanism of enuresis and its relationship to upper airway obstruction are reviewed here with reference to the findings of polysomnography and sleep cystometry.

Nitrazepam in patients with sleep apnoea: a double-blind placebo-controlled study

We wanted to assess whether benzodiazepines worsen sleep apnoea, since their use in such patients has been controversial. Fourteen male patients with mild to moderate obstructive sleep apnoea were investigated in a placebo-controlled, double-blind study evaluating the influence of nitrazepam (NIT) on apnoea frequency and severity. Each patient was given oral nitrazepam 5 or 10 mg, or corresponding placebo, in a randomized order on three separate nights. Wash-out time was one week. A complete sleep study was undertaken at each study night. Eleven patients completed the study. Although there were individuals with marked variability in apnoea index between the three study nights, there was no significant change in apnoea index or minimum arterial oxygen saturation with any of the two nitrazepam dosages studied. Only 3 out of 11 patients had a higher apnoea index after both nitrazepam doses compared to placebo, and in these patients the increase in sleep-disordered breathing was of marginal clinical significance. Nitrazepam caused a modest increase in total sleep time and a decrease in rapid eye movement (REM) sleep. These results demonstrate that nitrazepam does not worsen sleep apnoea in patients with mild to moderate sleep apnoea. The previously reported sleep apnoea promoting effects of benzodiazepines may be restricted to a small subgroup of patients with sleep-disordered breathing.

Effect of octreotide, a somatostatin analog, on sleep apnea in patients with acromegaly

OBJECTIVE

To determine the effects of octreotide, a somatostatin analog, on the severity of sleep apnea and on growth hormone levels in patients with acromegaly.

DESIGN

Open-label, prospective study.

SETTING

Tertiary referral hospital.

PATIENTS

19 patients with active acromegaly.

INTERVENTION

Octreotide in a 6-month, stepwise incremental dosage.

MEASUREMENTS

Sleep studies and indices of hormonal activity (levels of insulin-like growth factor 1 [IGF-1] and growth hormone).

RESULTS

A 50% decrease occurred in the respiratory disturbance index (baseline compared with 6 months, 39 events/h compared with 19 events/h; P = 0.0002), and a 40% decrease occurred in total apnea time (27.6% of total sleep time compared with 15.1%; P = 0.001). Indices of oxygen desaturation, sleep quality, and subjective sleepiness improved after 6 months of octreotide. A parallel decrease was noted in mean levels of growth hormone (40.0 micrograms/L compared with 9.1 micrograms/L; P = 0.003) and IGF-1 (107 nmol/L compared with 47 nmol/L; P = 0.0001). However, no correlation was noted between the decrease in the total amount of sleep time spent in apnea and the decrease in growth hormone levels (rho = -0.35; P > 0.2). The residual respiratory disturbance index after 6 months of treatment was similar in patients who improved, regardless of whether or not biochemical remission (IGF-1 < 35 nmol/L) occurred.

CONCLUSIONS

Improvement in indices of sleep apnea severity occurs in association with octreotide treatment in patients with sleep apnea and acromegaly. However, sleep apnea may either persist despite normalization of growth hormone levels or may improve markedly even if there is only partial biochemical remission.

Medroxyprogesterone acetate and ethanol-induced exacerbation of obstructive sleep apnea

OBJECTIVE

To determine if medroxyprogesterone acetate (MPA) can block the ethanol-induced worsening of obstructive sleep apnea.

DESIGN

Randomized, double-blind, placebo-controlled, crossover trial with 1 week treatment periods.

SETTING

A university-based pulmonary sleep laboratory.

PATIENTS

Fourteen patients with previously diagnosed obstructive sleep apnea not currently receiving any form of therapy for the disorder. Eight patients completed the entire protocol.

INTERVENTIONS

Baseline overnight polysomnography was performed. On the second study night, subjects ingested 1 ml/kg body weight 50 percent ethanol prior to repeat overnight polysomnography. If sleep apnea worsened, subjects then received either MPA (20 mg by mouth, three times a day) or placebo for 7 days then underwent repeat polysomnography with the same ethanol dose. A washout period followed, then, the other drug was taken, followed again by polysomnography with antecedent ethanol ingestion.

MEASUREMENTS AND RESULTS

Apnea-hypopnea indices (AHI) increased from 9.6 +/- 5.3 events/h (baseline) to 20.2 +/- 16.0 events/h on the ethanol night (p = 0.03). Low oxygen saturation (SaO2) fell to 79.2 +/- 5.1 percent on the ethanol night compared to baseline, 85.0 +/- 3.7 percent (p < 0.01). MPA improved AHI, nonrapid eye movement AHI, low SaO2, mean saturation nadir, number of desaturations between 80 and 90 percent, and the mean event desaturation when compared with the ethanol alone night. All these parameters were likewise improved when compared with placebo, although only the mean saturation nadir showed statistical significance. These findings were unchanged when also examined for the initial 3 hours of study.

CONCLUSIONS

In obstructive sleep apnea patients whose disease is made worse by ethanol ingestion, MPA appears to improve oxygenation during obstructive events but not to improve their number or length.

Acute effects of transdermal nicotine on sleep architecture, snoring, and sleep-disordered breathing in nonsmokers

Previous research has suggested that nicotine may be therapeutically useful in the treatment of sleep-disordered breathing. The development of transdermal nicotine delivery systems has allowed us to test the overnight effectiveness of nicotine. Twenty nonsmoking subjects (10 men, 10 women) were recruited on the basis of a history of habitual snoring that was confirmed by overnight laboratory monitoring. Subjects were then randomized (double-blind crossover design) to receive either placebo or an active patch that delivers 11 mg of nicotine over a 24-h period. Patches were applied at 6 P.M. and removed at 6 A.M. the following morning, at which time venous blood was obtained for determination of serum nicotine concentrations. Polysomnography was performed using standard techniques to assess sleep architecture and sleep-disordered breathing. Snoring was monitored with a sound-level meter and quantitatively analyzed to determine the snoring index (SI) (number of snores per hour of sleep) and mean and maximum snoring intensities. The age of the subjects was 46.9 +/- 11.4 yr (mean +/- SD) and their mean body mass index (BMI) 33.3 +/- 4.6 kg/m2. A mean nicotine level was nondetectable with placebo and 7.8 +/- 2.3 ng/ml with wearing of an active patch. Nicotine decreased total sleep time (TST) by 33 min (p < or 0.01), sleep efficiency from 89.7 to 83.5% (p < or = 0.01), and percent rapid eye movement (REM) sleep from 18.8 to 15.1% (p < or = 0.01), and prolonged initial sleep latency (ISL) from 6.7 to 18.2 min (p < or = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of short-term hormone replacement in the treatment of obstructive sleep apnoea in postmenopausal women

BACKGROUND

Women appear to be increasingly susceptible to snoring and sleep disordered breathing after the menopause. This observation, coupled with the considerable sex difference in sleep apnoea, may be explained on the basis of a protective effect of female hormones. This study was carried out to determine whether hormone replacement therapy has a role in the management of obstructive sleep apnoea in postmenopausal women.

METHODS

The effect of short-term (mean (SE) 50 (3) days) hormone replacement therapy with either oestrogen alone or in combination with progesterone on sleep disordered breathing was investigated in 15 postmenopausal women with moderate obstructive sleep apnoea. The effect of treatment on the ventilatory response to hypoxia and hypercapnia was assessed in 10 patients.

RESULTS

There was no reduction in the clinical severity of obstructive sleep apnoea after hormone treatment despite an increase in the serum oestrogen level from 172 (23) to 322 (33) pmol/l. There was a small but clinically insignificant reduction in the apnoea/hypopnoea index during REM sleep from 58 (6) to 47 (7). There was no difference in response between the oestrogen only group and the oestrogen plus progesterone group. Hypercapnic ventilatory responsiveness did not change with hormone treatment, but an change with hormone treatment, but an increase in hypoxic ventilatory responsiveness was observed.

CONCLUSIONS

These data indicate that short-term hormone replacement is unlikely to have an effective role in the clinical management of postmenopausal women with obstructive sleep apnoea. The observed reduction in the apnoea/hypopnoea index during REM sleep, however, suggests that longer term treatment, or the use of higher doses, may have an effect.

Comparison of the effects of acetazolamide and aminophylline on apnea incidence and on ventilatory response to CO2 in preterm infants

Acetazolamide (ACTZ) reduces sleep apnea in adults exposed to high altitude and augments the ventilatory response to CO2. In order to determine the effect of ACTZ on the ventilatory response to CO2 and the incidence of apnea in preterm infants, 7 infants (BW, 1070 +/- 191 g; postnatal age, 9 +/- 7 days) were randomized to receive ACTZ (5 mg/kg/dose Q6h for 36 hr) and 7 infants (BW, 1092 +/- 292 g; post-natal age, 5 +/- 2 days) received aminophylline (AMINO; 8 mg/kg bolus then 2.5 mg/kg Q12h for 36 hr). Minute ventilation (VE), end-tidal CO2 (PETCO2), ventilatory response to CO2, number of apneic episodes (> or = 15 sec duration), and arterial blood gases were measured before and 24-36 hr after starting therapy. In the AMINO group there was a significant decrease in apnea frequency from 6 +/- 1 to 2 +/- 2 episodes over an 8 hr epoch (P < 0.05), while no significant change was observed in the ACTZ group. The end-tidal CO2 decreased significantly from 44 +/- 7 to 38 +/- 6 mmHg in the AMINO group and from 47 +/- 5 to 36 +/- 5 mmHg in the ACTZ (P < 0.05), which lead to a shift to the left of the CO2-response curve in both groups. The slope of the CO2 response curve did not change significantly in the AMINO group and decreased in the ACTZ group. There was a significant decrease of pH from 7.43 to 7.26 in the ACTZ group, whereas in the AMINO group pH increased from 7.38 to 7.44.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperekplexia: report of a nonfamilial adult onset case associated with obstructive sleep apnea and abnormal brain nuclear tomography

We report the unique occurrence of hyperekplexia and obstructive sleep apnea (OSA) in a 48-year-old male. Polysomnography and multiple sleep latency testing excluded cataplexy, which can be confused with startle attacks. A new imaging finding was a nuclear tomography abnormality in the left frontal lobe. We postulate that this finding may represent a functional cortical lesion of a descending pathway that normally inhibits the startle reflex. Serious complications of pharmacotherapy with clonazepam, the drug of choice for hyperekplexia, can be avoided by first evaluating for OSA.

Theophylline therapy in sleep apnoea syndrome

There is evidence that theophylline improves obstructive sleep apnoea, although the existing studies are not comparable because of different patient groups, methods and treatment regimes and therefore may give partly conflicting results. In our opinion, patients with mild or moderate sleep apnoea syndrome, who do not need nasal ventilation therapy urgently, or who are not at a high cardiovascular risk, are the favourite group for theophylline therapy and an attempt in oral treatment in this group of patients is recommendable, since all other drugs have failed. Serum theophylline level should be lower than in anti-obstructive therapy, because of its otherwise deleterious effect in sleep structure. The improvement in apnoea index, when responding is not only a short-term effect, but lasts over a long-term treatment period, although patients should still be monitored, because of the possibility of worsening in some cases. The reason for responding and not responding in different patients remains unclear, and further studies are needed to investigate the precise mechanisms of action of theophylline in sleep apnoea, which include central and peripheral effects, to establish predictors for treatment in different groups of sleep apnoea patients.

[Long-term treatment of sleep apnea with evening administration of oral retard theophylline]

In 776 patients suffering from sleep apnoea long-term treatment with sustained-release theophylline was investigated. Responders show a significant reduction of apnoea phases. Using an individual theophylline dosage with morning theophylline concentrations between 5 and 8 micrograms/ml, only few side effects occurred. Positive effects on cardiopulmonary capacity were seen.

Intractable hiccups and sleep apnea syndrome in multiple sclerosis: report of two cases

Two cases of multiple sclerosis associated with intractable hiccups (IH) and sleep apnea syndrome (SAS) are reported. Lesions were detected in the tegmentum of the medulla oblongata by magnetic resonance imaging. In one case, high dose methylprednisolone was remarkably effective for the IH. For the SAS, amitriptyline was effective in one case. The IH and SAS are thought to be important symptoms when a lesion occurs in the tegmentum of the medulla oblongata, including the paramedian and lateral reticular formations. If IH appears in conjunction with a lesion in the tegmentum of the medulla oblongata, one must be vigilant for the development of SAS.

[Theophylline in therapy of obstructive sleep apnea?]

We examined the effect of 375 mg theophylline at night in 95 patients (14 women, 81 men) with obstructive sleep apnoea. The apnoea-hypopnoea index decreased significantly from 20.9 +/- 17.2 to 13.5 +/- 15.8/hour, the nadir of oxygen saturation increased from 80.6 +/- 8.5 to 82.4 +/- 8%. A survey of the longterm effects of theophylline in 16 initially responding patients revealed after 31-922 (190 +/- 217) days therapy no statistically significant change of the apnoea-hypopnoea index; however, the nadir of oxygen saturation was lower compared to the beginning of the therapy (83.8 +/- > 79.3 +/- 7.6%). We believe that theophylline is useful in single cases of patients with obstructive sleep apnoea, but is necessary to reconfirm the positive effect.