Rarely, bites may cause widespread symptoms, with occasional fatalities.There are a few spiders that can bite human skin and cause a skin reaction, but spiders are blamed for many more reactions. In particular the misdiagnosis of infections and other skin ailments are commonly attributed to brown recluses. Cause
Spiders do not feed on humans and typically bites occur as a defense mechanism. This can occur from unintentional contact or trapping of the spider. Most spiders have fangs too small to penetrate human skin. Most bites by species large enough for their bites to be noticeable will have no serious medical consequences.Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. Pathophysiology
A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin.
Naratriptan (trade names include Amerge) is a triptan drug marketed by GlaxoSmithKline and is used for the treatment of migraine headaches. It is a selective 5-HT1 receptor subtype agonist. It was patented in 1987 and approved for medical use in 1997. Medical uses
Naratriptan is used for the treatment of the acute migraine attacks and the symptoms of migraine, including severe, throbbing headaches that sometimes are accompanied by nausea and sensitivity to sound or light. Efficacy
A meta-analysis of 53 clinical trials has shown that all triptans are effective for treating migraine at marketed doses and that naratriptan, although less effective than sumatriptan and rizatriptan was more effective than placebo in reducing migraine symptoms at two hours and efficacy was demonstrated in almost two thirds of subjects after four hours of treatment. Side effects
Side effects include: dizziness, drowsiness, tingling of the hands or feet, nausea, dry mouth and unsteadiness. If these effects persist or worsen, notify your doctor promptly. Side-effects which are unlikely and which should be promptly reported include: chest pain/pressure, throat pain/pressure, unusually fast/slow/irregular pulse, one-sided muscle weakness, vision problems, cold/bluish hands or feet, stomach pain, bloody diarrhea, mental/mood changes, and fainting. In the unlikely event you have a serious allergic reaction to this drug, seek immediate medical attention. Symptoms of a serious allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing (swelling of the throat).