Interaction between Doxycycline and some Antiepileptic Drugs

The mean half life of doxycycline given to seven patients on long-term diphenylhydantoin treatment was 7·2 ± 0·4 hours. In five patients on long-term carbamazepine treatment the half life was 8·4 ± 1·4 hours. In four patients on combined diphenylhydantoin and carbamazepine treatment the half life was 7·4 ± 0·7 hours. All these were significantly shorter than a mean half life of 15·1 ± 1·0 hours when doxycycline was given to nine control patients. Therefore doxycycline in normal doses given to patients taking diphenylhydantoin or carbamazepine may fail to maintain the minimum inhibitory concentration necessary for proper bacteriostasis. When doxycycline is given in association with agents known to induce drug metabolism the serum concentration of the antibiotic should be watched to see that bacteriostatic levels are maintained.     

Adults who survived repair of congenital oesophageal atresia and tracheo-oesophageal fistula.

One hundred and twenty five adults who were born before 1969 with oesophageal atresia or tracheo-oesophageal fistula or both and were managed at the Royal Children''s Hospital, Melbourne, were reviewed. Most enjoyed a normal life. Though over half had difficulties in swallowing and symptoms of gastro-oesophageal reflux, the symptoms occurred only occasionally and were regarded as inconsequential by most. One third of the patients had wheeze and a quarter had at least one episode of bronchitis a year, but these interfered little with daily activities. Overall, these results are encouraging for young patients with oesophageal atresia and their families.     

Intravenous gammaglobulin treatment in patients with hypogammaglobulinaemia.

Intravenous gammaglobulin was compared with the standard British intramuscular preparation in patients with hypogammaglobulinaemia and chronic bronchitis. Five patients were given six months'' treatment with the weekly intramuscular preparation and six months'' treatment with intravenous gammaglobulin given once every 18 days. During the trial they recorded symptoms of infection, absence from work, and sputum volume; lung function tests were performed during the intravenous treatment. The half life of the intravenous IgG and changes in serum IgG and C1q concentrations were also measured in seven other patients who received intravenous gammaglobulin every two weeks for 12 weeks. IgG concentrations, sputum volume, and infection scores were significantly better during intravenous treatment and there were no adverse effects from the intravenous gammaglobulin. These five patients were significantly more healthy when they received an intravenous gammaglobulin preparation, probably because the intravenous preparation increased serum IgG concentrations. Although longer studies are needed, intravenous gammaglobulin should be considered for patients with severe chest disease and those who cannot tolerate intramuscular injections.     

Study of Fatal Cases of Friedreich's Ataxia

A study of 82 fatal cases of Friedreich''s ataxia showed that over half the patients died of heart failure while nearly three-quarters had evidence of cardiac dysfunction during life. A high incidence of diabetes mellitus (23%) was another finding, and four patients developed diabetic ketosis terminally.     

What do multiple sclerosis patients and their caregivers perceive as unmet needs?

Background

It has been suggested that cerebrospinal fluid (CSF) CXCL13 is a diagnostic marker of Lyme neuroborreliosis (LNB), as its levels have been shown to be significantly higher in LNB than in several other CNS infections. Levels have also been shown to decline after treatment with intravenous ceftriaxone, but levels after treatment with oral doxycycline have previously not been studied. Like Borrelia burgdorferi, HIV also has neurotropic properties. Elevated serum CXCL13 concentrations have been reported in HIV patients, but data on CSF levels are limited.

Methods

We longitudinally analysed CSF CXCL13 concentrations in 25 LNB patients before and after oral doxycycline treatment. Furthermore, we analysed CSF CXCL13 concentrations in 16 untreated LNB patients, 27 asymptomatic untreated HIV-1 infected patients and 39 controls with no signs of infectious or inflammatory disease.

Results

In the longitudinal LNB study, initially high CSF CXCL13 levels declined significantly after doxycycline treatment, which correlated to a decreased CSF mononuclear cell count. In the cross-sectional study, all the LNB patients had CSF CXCL13 levels elevated above the lowest standard point of the assay (7.8 pg/mL), with a median concentration of 500 pg/mL (range 34–11,678). Of the HIV patients, 52% had elevated CSF CXCL13 levels (median 10 pg/mL, range 0–498). There was a clear overlap in CSF CXCL13 concentrations between LNB patients and asymptomatic HIV patients. All but one of the 39 controls had CSF CXCL13 levels below 7.8 pg/mL.

Conclusions

We confirm previous reports of highly elevated CSF CXCL13 levels in LNB patients and that these levels decline after oral doxycycline treatment. The same pattern is seen for CSF mononuclear cells. CSF CXCL13 levels are elevated in neurologically asymptomatic HIV patients and the levels overlap those of LNB patients. The diagnostic value of CSF CXCL13 in LNB remains to be established.     

Advances and challenges in predicting the impact of lymphatic filariasis elimination programmes by mathematical modelling

Background

Infection with the filarial nematode Onchocerca volvulus can lead to severe dermatitis, visual impairment, and ultimately blindness. Since the currently used drug, ivermectin does not have macrofilaricidal or strong permanent sterilising effects on the adult worm, more effective drugs are needed to complement the use of ivermectin alone. Wolbachia endosymbiotic bacteria in filariae have emerged as a new target for treatment with antibiotics which can lead to long -term sterilization of the adult female filariae.

Methods

In the Central Region of Ghana, 60 patients were recruited, allocated into four groups and treated with 200 mg doxycycline per day for 2 weeks, 4 weeks, 6 weeks respectively. Untreated patients served as controls. Some of the treated patients and the untreated controls were given 150 μg/kg ivermectin 8 months after the start of doxycycline treatment.

Results

A follow up study 18 months post treatment showed that when using doxycycline alone there was a significant reduction of microfilarial (mf) loads in patients treated for either 4 or 6 weeks. However, there was no significant difference between the untreated controls and those given the 2 weeks regimen. Although no significant difference was demonstrated between the 4 and 6 weeks regimens, there was a trend observed, in that, microfilarial reduction appeared to have been greater following the 6 weeks regimen. Twelve months after ivermectin (i.e. 20 months after doxycycline) treatment, 8 out of 11 ivermectin-alone treated patients were mf-positive. In contrast, 1 out of the 7 patients treated for 4 weeks with doxycycline and none of the 4 patients treated for 6 weeks doxycycline (who were available for re-examination) were mf-positive after the combined treatment of doxycycline plus ivermectin treatment.

Conclusion

Treatment of onchocerciasis with doxycycline for 4 weeks is effective. Nonetheless, mf reduction appeared to be greater in the 6 weeks regimen. It is recommended that until further studies are carried out i.e. 4 weeks treatment with doxycycline is proven equivalent to the 6 weeks, selected groups of onchocerciasis patients should be treated for 6 weeks with doxycycline. As discussed earlier, this treatment should be accompanied by two doses of ivermectin.     

Obituaries

The outcome in 110 patients first treated with radioiodine (mean dose 6.56 mCi) for hyperthyroid Graves'' disease in 1980 was reviewed. In 23% of the patients the disease had not been controlled by the initial dose after 3 months, and 17% were given one or two more doses. Within 2 years 65% of the patients required replacement thyroxine therapy. Although about half of the patients were biochemically hypothyroid 3 months after the last dose of iodine 131, this condition was transient in a third of them; five of these patients even became hyperthyroid again. Patients with transient, as opposed to permanent, hypothyroidism at 3 months tended to be clinically euthyroid but to have residual palpable thyroid tissue and only a modest reduction in the serum thyroxine level. It is therefore recommended that patients not overtly hypothyroid 3 months after treatment with 131I be observed still longer before thyroxine replacement therapy is instituted.     

The modulation in subunits e and g amounts of yeast ATP synthase modifies mitochondrial cristae morphology

Subunits e and g of Saccharomyces cerevisiae ATP synthase are required to maintain ATP synthase dimeric forms. Mutants devoid of these subunits display anomalous mitochondrial morphologies. An expression system regulated by doxycycline was used to modulate the expression of the genes encoding the subunits e and g. A decrease in the amount of subunit e induces a decrease in the amount of subunit g, but a decrease in the amount of subunit g does not affect subunit e. The loss of subunit e or g leads to the loss of supramolecular structures of ATP synthase, which is fully reversible upon removal of doxycycline. In the absence of doxycycline, mitochondria present poorly defined cristae. In the presence of doxycycline, onion-like structures are formed after five generations. When doxycycline is removed after five generations, cristae are mainly observed. The data demonstrate that the inner structure of mitochondria depends upon the ability of ATP synthase to make supramolecular structures.     

Health of long term benzodiazepine users

The physical and psychological health of long term (over one year) users of benzodiazepines in one general practice was assessed by patients'' self reporting of illness and by general practitioners'' records. Of 3741 patients registered with the practice, 82 had been prescribed a benzodiazepine, and 64 of these agreed to enter the study. All but five of these patients were over 40 years of age, nearly a third (19) were given a diagnosis related to depression by interviewers, and between a third and a half reported a current physical illness.Long term treatment with benzodiazepines is not necessarily optimum management but may reflect the realities of general practice.     

Randomised controlled trial of antibiotics in patients with cough and purulent sputum.

Two hundred and twelve adults with cough and purulent sputum of up to one week''s duration were allocated randomly to treatment with doxycycline or placebo capsules for up to 10 days. Cough, purulent sputum, feeling "off colour," and time off work lasted as long in treatment and control groups, but running nose persisted for a shorter time in the doxycycline group. The number of new episodes of lower respiratory tract infections, vaginal infections, gastrointestinal upsets, and otitis media over the next six months were the same in both groups, but fewer new upper respiratory infections were experienced by the doxycycline-treated patients. There is no consensus among doctors about using antibiotics in patients with cough and purulent sputum, and these results indicate that otherwise healthy people with these symptoms will usually get better without antibiotic treatment.     

Oral Doxycycline Reduces Pterygium Lesions; Results from a Double Blind,Randomized, Placebo Controlled Clinical Trial

Purpose

To determine whether oral doxycycline treatment reduces pterygium lesions.

Design

Double blind, randomized, placebo controlled clinical trial.

Participants

98 adult patients with primary pterygium.

Methods

Patients were randomly assigned to receive 100 mg oral doxycycline twice a day (49 subjects), or placebo (49 subjects), for 30 days. Photographs of the lesion were taken at the time of recruitment and at the end of the treatment. Follow-up sessions were performed 6 and 12 months post-treatment. Statistical analyses for both continuous and categorical variables were applied. p values of less than 0.05 were considered to indicate statistical significance.

Main Outcome Measures

The primary endpoint was the change in lesion size after 30 days of treatment.

Results

The primary endpoint was not met for the whole population but subgroup analysis showed that doxycycline was effective in patients of Caucasian origin while other ethnicities, mostly Hispanic, did not respond to the treatment. Moreover, there was a correlation between age and better response (p = 0.003). Adverse events were uncommon, mild, and in agreement with previous reports on short doxycycline treatments.

Conclusions

Oral doxycycline was superior to placebo for the treatment of primary pterygia in older Caucasian patients. These findings support the use of doxycycline for pterygium treatment in particular populations.

Trial Registration

European Union Clinical Trials Register EudraCT 2008-007178-39     

A case of Kartagener's syndrome: Importance of early diagnosis and treatment

Kartagener''s syndrome is a very rare congenital malformation comprising of a classic triad of sinusitis, situs inversus and bronchiectasis. Primary ciliary dyskinesia is a genetic disorder with manifestations present from early life and this distinguishes it from acquired mucociliary disorders. Approximately one half of patients with primary ciliary dyskinesia have situs inversus and, thus are having Kartagener syndrome. We present a case of 12 year old boy with sinusitis, situs inversus and bronchiectasis. The correct diagnosis of this rare congenital autosomal recessive disorder in early life is important in the overall prognosis of the syndrome, as many of the complications can be prevented if timely management is instituted, as was done in this in this case.     

The time of determination of gynoparae and males in the bird cherry–oat aphid, Rhopalosiphum padi

Apterous exules of Rhopalosiphum padi which experienced short photoperiods only during the first half of their nymphal life all produced gynoparae which made up 57% of the offspring produced in the first 7 days of the mother's reproductive life. Short photoperiods during the second half of a mother's nymphal life did not induce the production of gynoparae. However, when short photoperiods were experienced throughout a mother's nymphal life significantly more gynoparae (82%) were produced. Ten per cent of the offspring of mothers that experienced short photoperiods only during their adult life developed into gynoparae. Of the offspring reared in short photoperiods, but born to mothers reared and kept in long photoperiods, 30% developed into gynoparae. When mothers were exposed to short photoperiods in their adult life and their offspring so treated, then 90% of the offspring developed into gynoparae. Males only occurred amongst the last offspring of mothers that experienced short photoperiods in either the first or the second half of their nymphal life.     

Prospective trial of operative versus non-operative treatment of severe vesicoureteric reflux in children: five years' observation. Birmingham Reflux Study Group.

Children with severe vesicoureteric reflux were allocated randomly to either operative or non-operative treatment and followed up. Altogether 161 children were observed for two years, of whom 104 were followed up for five years. Reflux was abolished in 98% of ureters reimplanted, but more than half of the patients treated non-operatively continued to show severe reflux at five years. Two patients progressed to end stage renal failure, and a further four with extensive bilateral renal scarring became hypertensive. There were no significant differences between treatment groups in the incidence of breakthrough urinary infection, renal excretory function and concentrating ability, renal growth, progression of existing renal scars, or new scar formation. Progressive scarring occurred at all ages but was significantly more common during the first two years'' observation. Furthermore, new scars developed exclusively during the first two years'' observation, affecting 10 children aged 2-7 at allocation. Neither treatment can claim superiority or fully protect the kidneys from further damage, and efforts must continue to be directed towards identifying those at risk before scarring develops.     

Babies with spina bifida treated without surgery: parents' views on home versus hospital care.

From 1971 to 1981, 98 babies born with meningomyelocoele at the North Staffordshire Hospital Centre''s district maternity hospital, were thought not suitable for surgery. Sixty three survived for more than one week. Over the period the hospital''s policy changed: initially all such babies were kept in hospital, but later parents were given the choice of taking their baby home for palliative and terminal care. In an attempt to determine parents'' views on the care of their baby the parents of 44 of the babies who survived to one week were traced in 1985-6, five to 14 years later; 80 of them were asked how they felt about the lives and deaths of their babies. Eighteen babies had been taken home, and they had lived longer than the 26 who had been cared for in hospital. Parents whose baby had remained in hospital were sadder than those who had taken their baby home when they looked back at their experiences, and they also considered that their baby''s life had been of poor quality. Most of those who had taken their baby home had a more positive view of their child''s life. The figures suggest that the bereavement process after a baby''s death is longer than has been thought, but despite residual sadness just over half of the parents interviewed thought that something positive had come out of their experience.     

Treatment of Mycoplasma genitalium. Observations from a Swedish STD Clinic

Objectives

To evaluate therapy for Mycoplasma genitalium infection with doxycycline or azithromycin 1 g compared to five days of azithromycin (total dose 1.5 g).

Methods

A retrospective case study was performed among patients attending the STD-clinic in Falun, Sweden 1998–2005. All patients with a positive PCR test for M. genitalium were routinely offered a test of cure (toc). Response to doxycycline for 9 days, azithromycin 1 g single dose and extended azithromycin (500 mg on day 1 followed by 250 mg o.d. for 4 days) was determined. In patients with treatment failure after azithromycin, macrolide resistance was monitored before and after treatment. Furthermore, the rate of macrolide resistance was monitored for positive specimens available from 2006–2011.

Results

The eradication rate after doxycycline was 43% (48% for women and 38% for men), for azithromycin 1 g 91% (96% for women and 88% for men) and for extended azithromycin 99% (100% for women and 93% for men). Macrolide resistance developed in 7/7 examined (100%) of those testing positive after azithromycin 1 g, but in none of those treated with extended azithromycin. Macrolide resistance before treatment increased from 0% in 2006 and 2007 to 18% in 2011.

Conclusions

These findings confirm the results from other studies showing that doxycycline is inefficient in eradicating M. genitalium. Although azithromycin 1 g was not significantly less efficient than extended dosage, it was associated with selection of macrolide resistant M. genitalium strains and should not be used as first line therapy for M. genitalium. Monitoring of M. genitalium macrolide resistance should be encouraged.     

Comparison of Serological Response to Doxycycline versus Benzathine Penicillin G in the Treatment of Early Syphilis in HIV-Infected Patients: A Multi-Center Observational Study

Background

While doxycycline is recommended as an alternative treatment of syphilis in patients with penicillin allergy or intolerance, clinical studies to compare serological response to doxycycline versus benzathine penicillin in treatment of early syphilis among HIV-infected patients remain sparse.

Methods

We retrospectively reviewed the medical records of HIV-infected patients with early syphilis who received doxycycline 100 mg twice daily for 14 days (doxycycline group) and those who received 1 dose of benzathine penicillin (2.4 million units) (penicillin group) between 2007 and 2013. Serological responses defined as a decline of rapid plasma reagin titer by 4-fold or greater at 6 and 12 months of treatment were compared between the two groups.

Results

During the study period, 123 and 271 patients in the doxycycline and penicillin group, respectively, completed 6 months or longer follow-up. Ninety-one and 271 patients in the doxycycline and penicillin group, respectively, completed 12 months or longer follow-up. Clinical characteristics were similar between the two groups, except that, compared with penicillin group, doxycycline group had a lower proportion of patients with secondary syphilis (65.4% versus 41.5%, P<0.0001) and a higher proportion of patients with early latent syphilis (25.3% versus 49.6%, P<0.0001). No statistically significant differences were found in the serological response rates to doxycycline versus benzathine penicillin at 6 months (63.4% versus 72.3%, P = 0.075) and 12 months of treatment (65.9% versus 68.3%, P = 0.681). In multivariate analysis, secondary syphilis, but not treatment regimen, was consistently associated with serological response at 6 and 12 months of follow-up.

Conclusions

The serological response rates to a 14-day course of doxycycline and a single dose of benzathine penicillin were similar in HIV-infected patients with early syphilis at 6 and 12 months of follow-up. Patients with secondary syphilis were more likely to achieve serological response than those with other stages.     

Primary ciliary dyskinesia (Siewert's / Kartagener's Syndrome): Respiratory symptoms and psycho-social impact

Background

Although the pathophysiological defect in primary ciliary dyskinesia (PCD; Siewert's / Kartagener's syndrome) is now well characterised, there are few studies of the impact of the condition upon health function, particularly in later life. This study assesses the health impact of the condition in a large group of patients. In addition, it assesses the similarity in age of diagnosis, symptoms and problems of those with situs inversus (PCD-SI) and those with situs solitus (PCD-SS).

Methods

Postal questionnaire sent to members of the UK Primary Ciliary Dyskinesia Family Support Group. The questionnaire contained the St. George's Respiratory Questionnaire (SGRQ) and the SF-36 questionnaire for assessing health status.

Results

93 questionnaires were returned, representing a 66% response rate. Replies were received from similar numbers of PCD-SI and PCD-SS. Individuals with PCD-SI did not show a significant tendency to be diagnosed earlier, and neither did they show any difference in their symptoms, or the relationship of symptoms to age. Respiratory symptoms were fairly constant up until the age of about 25, after which there was a slow increase in symptoms, and a decline in health status, patients over the age of 40 being about one and a half standard deviations below the mean on the physical component score of the PCS. Patients diagnosed earlier in life, and hence who had received more treatment for their condition, had better scores on the SGRQ Impact and Activity scores.

Conclusions

PCD is a chronic condition which has a progressively greater impact on health in the second half of life, producing significant morbidity and restriction of life style. Early diagnosis, and hence earlier treatment, may improve symptoms and the impact of the condition.     

Doxycycline improves cage activity,but not exercised,supraspinatus tendon and muscle in a rat model

The objective of this study was to investigate the effects of doxycycline, a broad-spectrum MMP inhibitor, on cage activity and exercised supraspinatus tendon and muscle using a Sprague-Dawley rat model of non-injurious exercise. Because exercise may alter muscle and tendon MMP activity and matrix turnover, we hypothesized that doxycycline would abolish the beneficial adaptations found with exercise but have no effect on cage activity muscle and tendon properties. Rats were divided into acute or chronic exercise (EX) or cage activity (CA) groups, and half of the rats received doxycycline orally. Animals in acute EX groups were euthanized 24 h after a single bout of exercise (10 m/min, 1 h) on a flat treadmill. Animals in chronic EX groups walked on a flat treadmill and were euthanized at 2 or 8 week time points. Assays included supraspinatus tendon mechanics and histology and muscle fiber morphologic and type analysis. Doxycycline improved tendon mechanical properties and collagen organization in chronic cage activity groups, which was not consistently evident in exercised groups. Combined with exercise, doxycycline decreased average muscle fiber cross-sectional area. Results of this study suggest that administration of doxycycline at pharmaceutical doses induces beneficial supraspinatus tendon adaptations without negatively affecting the muscle in cage activity animals, supporting the use of doxycycline to combat degenerative processes associated with underuse; however, when combined with exercise, doxycycline does not consistently produce the same beneficial adaptations in rat supraspinatus tendons and reduces muscle fiber cross-sectional area, suggesting that doxycycline is not advantageous when combined with activity.     

Abnormal Drug Metabolism after Barbiturate and Paracetamol Overdose

Drug-metabolizing capacity has been assessed by serial measurements of the plasma antipyrine half life in 11 patients with severe barbiturate intoxication and in 17 patients with acute hepatic necrosis due to paracetamol overdosage. Drug metabolism was strikingly enhanced after barbiturate over-dosage, and this effect was still present six weeks later. In contrast the antipyrine half life was greatly prolonged in patients with paracetamol-induced acute hepatic necrosis but returned to normal or near-normal values within seven to 21 days.